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Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2018	Feb. 15, 2019	Jun. 30, 2018
Document Information [Line Items]
Entity Registrant Name	APPFOLIO INC
Entity Central Index Key	0001433195
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Entity Shell Company	false
Amendment Flag	false
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Public Float			$ 1,036
Class A common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		15,833,617
Class B common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		18,071,665

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 74,076	$ 16,109
Investment securities—current	16,631	29,800
Accounts receivable, net	5,516	3,387
Prepaid expenses and other current assets	11,775	4,546
Total current assets	107,998	53,842
Investment securities—noncurrent	11,256	22,401
Property and equipment, net	6,871	6,696
Capitalized software, net	20,485	17,609
Goodwill	15,548	6,737
Intangible assets, net	5,895	1,725
Other assets	7,688	1,238
Total assets	175,741	110,248
Current liabilities
Accounts payable	1,481	610
Accrued employee expenses	12,377	10,710
Accrued expenses	8,281	4,289
Deferred revenue	3,414	7,080
Other current liabilities	1,447	1,223
Long-term debt, net—current portion	1,213	0
Total current liabilities	28,213	23,912
Long-term debt, net	48,602	0
Long-term deferred rent and other liabilities	7,080	1,257
Total liabilities	83,895	25,169
Commitments and contingencies (Note 9)
Stockholders’ equity:
Preferred stock, $0.0001 par value, 25,000 authorized and no shares issued and outstanding at December 31, 2018 and December 31, 2017	0	0
Additional paid-in capital	157,898	152,531
Accumulated other comprehensive loss	(178)	(209)
Treasury stock, at cost, 370,751 Class A shares	(21,562)	0
Accumulated deficit	(44,316)	(67,247)
Total stockholders’ equity	91,846	85,079
Total liabilities and stockholders’ equity	175,741	110,248
Class A common stock, $0.0001 par value, 250,000 shares authorized at December 31, 2018 and December 31, 2017; issued - 16,159 and 14,879, shares at December 31, 2018 and December 31, 2017; outstanding - 15,789 and 14,879 shares at December 31, 2018 and December 31, 2017, respectively;
Stockholders’ equity:
Common stock	2	1
Class B common stock, $0.0001 par value, 50,000 shares authorized at December 31, 2018 and December 31, 2017; 18,109 and 19,102 shares issued and outstanding at December 31, 2018 and December 31, 2017, respectively;
Stockholders’ equity:
Common stock	$ 2	$ 3

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Treasury stock, shares	370,751	370,751
Preferred Stock
Preferred stock, par value (usd per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	25,000,000	25,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Class A common stock
Common stock, par value (usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	16,159,000	14,879,000
Common stock, shares outstanding	15,789,000	14,879,000
Class B common stock
Common stock, par value (usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	18,109,000	19,102,000
Common stock, shares outstanding	18,109,000	19,102,000

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Revenue	$ 190,071	$ 143,803	$ 105,586
Costs and operating expenses:
Cost of revenue (exclusive of depreciation and amortization)	73,549	55,283	44,630
Sales and marketing	33,288	28,709	28,827
Research and product development	24,111	16,578	12,638
General and administrative	24,891	21,199	17,979
Depreciation and amortization	14,576	12,699	9,935
Total costs and operating expenses	170,415	134,468	114,009
Income (loss) from operations	19,656	9,335	(8,423)
Other (expense), net	(56)	(96)	(37)
Interest income, net	787	535	246
Income (loss) before provision for income taxes	20,387	9,774	(8,214)
Provision for income taxes	420	58	67
Net income (loss)	$ 19,967	$ 9,716	$ (8,281)
Net income (loss) per common share:
Basic (in usd per share)	$ 0.59	$ 0.29	$ (0.25)
Diluted (in usd per share)	$ 0.56	$ 0.28	$ (0.25)
Weighted average common shares outstanding:
Basic (in shares)	34,128	33,849	33,561
Diluted (in shares)	35,562	35,151	33,561

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 19,967	$ 9,716	$ (8,281)
Other comprehensive income (loss):
Changes in unrealized gains (losses) on investment securities	31	(158)	102
Comprehensive income (loss)	$ 19,998	$ 9,558	$ (8,179)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) shares in Thousands, $ in Thousands	Total	Common stock Class A common stock	Common stock Class B common stock	Additional paid-in capital	Accumulated other comprehensive loss	Treasury Stock	Accumulated deficit
Beginning balance (shares) at Dec. 31, 2015		9,005	24,541
Beginning balance at Dec. 31, 2015	$ 72,697	$ 1	$ 3	$ 141,528	$ (153)	$ 0	$ (68,682)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (shares)		140	1
Exercise of stock options	352			352
Stock-based compensation	4,495			4,495
Vesting of restricted stock units, net of shares withheld for taxes (shares)		10
Vesting of restricted stock units, net of shares withheld for taxes	127	$ 0		127
Vesting of early exercised shares (shares)		0
Vesting of early exercised shares	190	$ 0		190
Conversion of Class B stock to Class A stock (shares)		2,514	(2,514)
Conversion of Class B stock to Class A stock	0	$ 0	$ 0
Issuance of restricted stock awards (shares)		22	0
Issuance of restricted stock awards	0
Other comprehensive income (loss)	102				102
Net income (loss)	(8,281)						(8,281)
Ending balance (shares) at Dec. 31, 2016		11,691	22,028
Ending balance at Dec. 31, 2016	69,682	$ 1	$ 3	146,692	(51)	0	(76,963)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (shares)		165	0
Exercise of stock options	663			663
Stock-based compensation	6,618			6,618
Vesting of restricted stock units, net of shares withheld for taxes (shares)		88
Vesting of restricted stock units, net of shares withheld for taxes	(1,559)			(1,559)
Vesting of early exercised shares	117			117
Conversion of Class B stock to Class A stock (shares)		2,926	(2,926)
Conversion of Class B stock to Class A stock	0	$ 0
Issuance of restricted stock awards (shares)		9	0
Issuance of restricted stock awards	0
Other comprehensive income (loss)	(158)				(158)
Net income (loss)	9,716						9,716
Ending balance (shares) at Dec. 31, 2017		14,879	19,102
Ending balance at Dec. 31, 2017	85,079	$ 1	$ 3	152,531	(209)	0	(67,247)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative-effect adjustment resulting from adoption of ASU 2014-09	$ 2,964						2,964
Exercise of stock options (shares)	170	170	0
Exercise of stock options	$ 1,035			1,035
Stock-based compensation	7,187			7,187
Vesting of restricted stock units, net of shares withheld for taxes (shares)		113
Vesting of restricted stock units, net of shares withheld for taxes	(2,890)			(2,890)
Vesting of early exercised shares	35			35
Conversion of Class B stock to Class A stock (shares)		993	(993)
Conversion of Class B stock to Class A stock	0	$ 1	$ (1)
Issuance of restricted stock awards (shares)		5	0
Issuance of restricted stock awards	0	$ 0
Other comprehensive income (loss)	31				31
Repurchase of common stock (shares)		(371)
Repurchase of common stock	(21,562)					(21,562)
Net income (loss)	19,967						19,967
Ending balance (shares) at Dec. 31, 2018		15,789	18,109
Ending balance at Dec. 31, 2018	$ 91,846	$ 2	$ 2	$ 157,898	$ (178)	$ (21,562)	$ (44,316)

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash from operating activities
Net income (loss)	$ 19,967	$ 9,716	$ (8,281)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	14,576	12,699	9,935
Purchased investment premium, net of amortization	142	(39)	245
Amortization of deferred financing costs	60	63	63
Loss on disposal of property, equipment, and intangibles	22	97	41
Stock-based compensation	6,337	6,096	4,301
Lease abandonment	0	0	161
Changes in operating assets and liabilities:
Accounts receivable	(908)	(876)	(463)
Prepaid expenses and other current assets	(6,073)	(1,009)	(377)
Other assets	(4,447)	(84)	(103)
Accounts payable	614	(100)	(904)
Accrued employee expenses	1,219	3,243	2,223
Accrued expenses	3,281	271	1,148
Deferred revenue	(4,589)	(558)	2,685
Other liabilities	6,067	(148)	826
Net cash provided by operating activities	36,268	29,371	11,500
Cash from investing activities
Purchases of property and equipment	(2,102)	(2,213)	(4,242)
Additions to capitalized software	(12,304)	(10,455)	(11,166)
Purchases of investment securities	(29,516)	(26,648)	(31,551)
Sales of investment securities	20,900	15	12,559
Maturities of investment securities	32,819	16,474	21,337
Cash paid in business acquisition	(14,441)	0	0
Purchases of intangible assets	0	(1)	(2)
Net cash used in investing activities	(4,644)	(22,828)	(13,065)
Cash from financing activities
Proceeds from stock option exercises	1,035	663	352
Tax withholding for net share settlement	(3,127)	(1,796)	(111)
Principal payments under capital lease obligations	0	0	(29)
Purchase of treasury stock	(21,562)	0	0
Proceeds from issuance of debt	50,138	118	117
Principal payments on debt	(138)	(118)	(128)
Net cash provided by (used in) financing activities	26,346	(1,133)	201
Net increase (decrease) in cash and cash equivalents	57,970	5,410	(1,364)
Cash, cash equivalents and restricted cash
Beginning of period	16,536	11,126	12,490
End of period	74,506	16,536	11,126
Supplemental disclosure of cash flow information
Cash paid for interest	118	182	191
Cash paid for taxes	82	30	27
Noncash investing and financing activities
Purchases of property and equipment included in accounts payable and accrued expenses	518	21	261
Additions of capitalized software included in accrued and accrued employee expenses	825	374	458
Stock-based compensation capitalized for software development	1,087	759	431
Debt issuance and other financing costs accrued, not paid	$ 371	$ 0	$ 0

Consolidated Statements of Cash Flows - Reconciliation - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Cash Flows [Abstract]
Cash and cash equivalents	$ 74,076	$ 16,109	$ 10,699
Restricted cash included in other assets	430	427	427
Total cash, cash equivalents and restricted cash	$ 74,506	$ 16,536	$ 11,126	$ 12,490

Nature of Business	12 Months Ended
Nature of Business	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business	Nature of Business AppFolio, Inc. (“we,” "us" or "our") provides industry-specific, cloud-based business software solutions, services and data analytics to the real estate market, which comprises a significant majority of our revenue, and, to a lesser extent, to the legal market. Our mission is to revolutionize vertical industry businesses by providing great software and services. We believe we accomplish this mission by providing our customers with a system of record to automate essential business processes, a system of engagement to enhance business interactions between our customers and their clients and other stakeholders, and a system of intelligence designed to leverage data to predict and optimize business workflows in order to enable superior customer experiences and increase efficiency across our customers' businesses. Revenue generated from customers in our real estate market directly and indirectly account for more than 90% of our annual revenue. Real estate customers include third-party property managers, owner-operators and real estate investors who manage single- and multi-family residences, commercial associations, community properties, student housing, as well as mixed real estate portfolios. Our legal customers are typically small law firms that directly and indirectly account for less than 10% of our annual revenue.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

Basis of Presentation and Significant Accounting Policies

The accompanying Consolidated Financial Statements were prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”).

Except for the accounting policies for revenue recognition and deferred costs that were updated as a result of adopting ASU 2014-09, our significant accounting polices have been applied consistently to all years presented, unless otherwise stated.

The Company analyzes the expenses recognized in the statement of operations using the classification method based on the functional category to which the expense belongs.

Principles of Consolidation

The accompanying Consolidated Financial Statements include the operations of AppFolio, Inc. and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

Our investment in SecureDocs, Inc. (“SecureDocs”) is accounted for under the equity method of accounting as we have the ability to exert significant influence, but do not control and are not the primary beneficiary of the entity. Our investment in SecureDocs is not material and any income (loss) activity is not material individually or in the aggregate to our Consolidated Financial Statements for any period presented.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the dates of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ materially from those estimates. Assets and liabilities which are subject to judgment and use of estimates include the fair value of assets and liabilities assumed in business combinations, fair value of financial instruments, capitalized software costs, the recoverability of goodwill and long-lived assets, income taxes, useful lives associated with property and equipment and intangible assets, contingencies, and valuation and assumptions underlying stock-based compensation and other equity instruments. On an ongoing basis, management evaluates its estimates based on historical data and experience, as well as various other factors that management believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources.

Segment Information

Our chief operating decision maker reviews financial information presented on an aggregated and consolidated basis, together with revenue information for our core solutions, Value+ and other service offerings, principally to make decisions about how to allocate resources and to measure our performance. Accordingly, management has determined that we have one reportable and operating segment.

Concentrations of Credit Risk

Financial instruments that potentially subject us to credit risk consist principally of cash, accounts receivable, investment securities and notes receivable. We maintain cash balances at financial institutions in excess of amounts insured by United States government agencies or payable by the United States government directly. We place our cash with high credit, quality financial institutions. We invest in investment securities with a minimum rating of A by Standard & Poor's or A-1 by Moody's and regularly monitor our investment security portfolio for changes in credit ratings.

Concentrations of credit risk with respect to accounts receivable and revenue are limited due to a large, diverse customer base. No individual customer represented 10% or more of accounts receivable at December 31, 2018 and 2017 or revenue for the years ended December 31, 2018, 2017 and 2016.

Fair Value Measurements

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date.

Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Accounting Standard Codification (“ASC”) 820, Fair Value Measurements and Disclosures (“ASC 820”), describes a fair value hierarchy based on three levels of inputs, of which the first two are considered observable and the last unobservable, that may be used to measure fair value, which are the following:

Level 1 - Quoted prices in active markets for identical assets or liabilities or funds.

Level 2 - Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

Cash and Cash Equivalents and Restricted Cash

We consider all highly liquid investments, readily convertible to cash, and which have a remaining maturity date of three months or less at the date of purchase, to be cash equivalents. Cash and cash equivalents are recorded at fair value and consist primarily of bank deposits and money market funds.

Restricted cash of $0.4 million at December 31, 2018 and 2017, is comprised of certificates of deposits relating to collateral requirements for customer automated clearing house and credit card chargebacks and minimum collateral requirements for our insurance services, which are recorded in other long term assets.

Investment Securities

Our investment securities currently consist of corporate bonds, United States government agency securities ("Agency Securities") and certificates of deposit. We classify investment securities as available-for-sale at the time of purchase and reevaluate such classification at each balance sheet date. All investments are recorded at estimated fair value. Unrealized gains and losses for available-for-sale investment securities are included in accumulated other comprehensive income (loss), a component of stockholders’ equity. We classify our investments as current when the period of time between the reporting date and the contractual maturity is twelve months or less and as noncurrent when the period of time between the reporting date and the contractual maturity is more than twelve months.

We evaluate our investments to assess whether those with unrealized loss positions are other than temporarily impaired. We consider impairments to be other than temporary if they are related to deterioration in credit risk or if it is likely we will sell the securities before the recovery of their cost basis. Declines in value judged to be other than temporary are determined based on the specific identification method and are reported in other (expense), net in the Consolidated Statements of Operations.

Accounts Receivable

Accounts receivable are recorded at the invoiced amount, net of an allowance for doubtful accounts. The allowance for doubtful accounts is based on historical loss experience, the number of days that receivables are past due, and an evaluation of the potential risk of loss associated with delinquent accounts. Accounts receivable considered uncollectable are charged against the allowance for doubtful accounts when identified. We do not have any off-balance sheet credit exposure related to our customers. At December 31, 2018 and 2017, our allowance for doubtful accounts was not material.

Property and Equipment

Property and equipment is stated at cost, less accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of assets. The estimated useful lives of our property and equipment are as follows:



Asset Type		Depreciation Period
Data center and computer equipment		3 years
Furniture and fixtures		7 years
Office equipment		2 to 5 years
Leasehold improvements		Shorter of remaining life of lease or asset life

Repair and maintenance costs are expensed as incurred. Renewals and improvements are capitalized. Assets disposed of or retired are removed from the cost and accumulated depreciation accounts and any resulting gain or loss is reflected in our results of operations.

Leases

Leases are evaluated and classified as either operating or capital leases. All of our office space leases are operating leases.

Rent expense under operating leases is recognized on a straight-line basis over the lease term. The difference between recognized rent expense and the rent payment amount is recorded as an increase or decrease in deferred rent liability. If the lease has tenant allowances from the lessor for certain improvements made to the leased property, these allowances are capitalized as leasehold improvements. Tenant allowances and rent holidays in lease agreements are recognized as a deferred rent credit, which is amortized on a straight-line basis over the lease term as a reduction of rent expense.

The deferred rent liability was amortized as a reduction of rent expense over the lives of the leases. As of December 31, 2018, and 2017 the deferred rent liability was $6.9 million and $1.1 million, respectively, and is included in long-term deferred rent and other liabilities, on the Consolidated Balance Sheets.

Capitalized Software Development Costs

Software development cost consist of certain payroll and stock compensation costs incurred to develop functionality of our internal-use software solutions. We capitalize certain software development costs for new offerings as well as significant upgrades and enhancements to our existing software solutions. Capitalized software development costs are amortized using the straight-line method over an estimated useful life of three years. We do not transfer ownership of our software, or lease our software, to third parties. We believe there are two key estimates within the capitalized software balance, which are the determination of the useful life of the software and the determination of the amounts to be capitalized.

We determine the amount of internal software costs to be capitalized based on the amount of time spent by our software engineers on projects. Costs associated with building or significantly enhancing our software solutions and new internally built software solutions are capitalized, while costs associated with planning new developments and maintaining our software solutions are expensed as incurred. There is judgment involved in estimating the stage of development as well as estimating time allocated to a particular project. A significant change in the time spent on each project could have a material impact on the amount capitalized and related amortization expense in subsequent periods.

Goodwill and Intangible Assets

Goodwill represents the excess of the purchase price over the estimated fair value of the net tangible and identifiable intangible assets acquired in business combinations. Goodwill is tested for impairment at least annually at the reporting unit level or at other times if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount.

We have the option to assess goodwill for possible impairment by performing a qualitative analysis to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. A quantitative assessment is performed if the qualitative assessment results in a more-likely-than-not determination or if a qualitative assessment is not performed. The quantitative assessment considers whether the carrying amount of a reporting unit exceeds its fair value, in which case an impairment charge is recorded to the extent that the reporting unit’s carrying value exceeds its fair value.

We have one reporting unit and we test for goodwill impairment annually during the fourth quarter of the calendar year. Based on the assessment performed November 1, 2018, we determined it was unlikely that our reporting unit fair value was less than its carrying value and no quantitative impairment test assessment was required. There were no indicators that our goodwill has become impaired since that date, and as such, there was no impairment of goodwill as of November 1, 2018 or December 31, 2018.

No impairment losses were recorded for goodwill during the years ended December 31, 2018, 2017 and 2016.

Intangible assets primarily consist of customer and partner relationships, acquired technology, trademarks, domain names and patents, which are recorded at cost, less accumulated amortization. We determine the appropriate useful life of our intangible assets by performing an analysis of expected cash flows of the acquired assets. Intangible assets are amortized over their estimated useful lives on a straight-line basis, which approximates the pattern in which the economic benefits of the assets are consumed.

Impairment of Long-Lived Assets

We assess the recoverability of our long-lived assets when events or changes in circumstances indicate that the carrying value of an asset may not be recoverable or that the useful lives of those assets are no longer appropriate. An impairment charge would be recognized when the carrying amount of a long-lived asset or asset group is not recoverable and exceeds its fair value. The carrying amount of a long-lived asset or asset group is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset or asset group. There were no impairment charges related to the identified long-lived assets for the years ended December 31, 2018, 2017 and 2016.

Business Combinations

The results of a business acquired in a business combination are included in our Consolidated Financial Statements from the date of acquisition. We allocate the purchase price, including the fair value of contingent consideration, to the identifiable assets and liabilities of the acquired business at their acquisition date fair values. The excess of the purchase price over the amount allocated to the identifiable assets and liabilities, if any, is recorded as goodwill.

Determining the fair value of assets acquired and liabilities assumed requires management to make significant judgments and estimates, including the selection of valuation methodologies, estimates of future revenue and cash flows, discount rates and selection of comparable companies.

Acquisition-related transaction costs are not included as a component of consideration transferred, but are accounted for as an operating expense in the period in which the costs are incurred.

Revenue Recognition

We generate revenue from our customers primarily for subscriptions to access our core solutions and Value+ services for our cloud-based software solutions. Revenue is recognized upon transfer of control of promised services in an amount that reflects the consideration we expect to receive in exchange for those services. We enter into contracts that can include various combinations of services, which are generally capable of being distinct, distinct within the context of the contract, and accounted for as separate performance obligations. Revenue is recognized net of any taxes collected from customers, which are subsequently remitted to governmental authorities. Refer to Note 13, Revenue and Other Information for the disaggregated breakdown of revenues between core solutions, Value+ services and other revenues.

Core Solutions

We charge our customers on a subscription basis for our core solutions. Our subscription fees are designed to scale to the size of our customers' businesses. Subscription fees for our core solutions are charged on a per-unit per-month basis for our property management software solution and on a per-user per-month basis for our legal software solution. Our customers do not have rights to the underlying software code of our solutions, and, accordingly, we recognize subscription revenue over time on a straight-line basis over the contract term beginning on the date that our service is made available to the customer. The term of our core solutions subscription agreements typically ranges from one month to one year. We typically invoice our customers for subscription services in monthly or annual installments, in advance of the subscription period.

Value+ Services

We charge our customers on a subscription or usage basis for our Value+ services. Subscription-based fees are charged on a per-unit basis. We typically invoice our customers for subscription-based services in monthly installments, in advance of the subscription period. We recognize revenue for subscription-based services over time on a straight-line basis over the contract term beginning on the date that our service is made available to the customer. Usage-based fees are charged on a flat rate per transaction basis with no minimum usage commitments. We recognize revenue for usage-based services in the period the service is rendered. We generally invoice our customers for usage-based services on a monthly basis for services rendered in the preceding month. In addition, some subscription or usage-based Value+ services, such as fees for electronic payment services, are paid by either our customers or clients of our customers at the time the services are rendered.

We work with third-party partners to provide certain of our Value+ services. For these Value+ services, we evaluate whether we are the principal, and report revenues on a gross basis, or the agent, and report revenues on a net basis. In this assessment we consider if we obtain control of the specified services before they are transferred to the customer, as well as other indicators such as whether we are the party primarily responsible for fulfillment, and whether we have discretion in establishing price.

Other Revenues

Other revenues include fees from one-time services related to the implementation of our software solutions and other recurring or one-time fees related to our customers who are not otherwise using our core solutions. This includes legacy customers of businesses we have acquired where the customers haven't migrated to our core solutions. The fees for implementation and data migration services are billed upon signing our core subscription contract and are not recognized until the core solution is accessible and fully functional for our customer's use. Other services are billed when the services rendered are completed and delivered to the customer or billed in advance and deferred over the subscription period.

Contracts with Multiple Performance Obligations

Many of our contracts with customers contain multiple performance obligations. Determining whether products and services are considered distinct performance obligations that should be accounted for separately versus together may require significant judgment. We account for individual performance obligations separately if they are distinct. The performance obligations for these contracts include access and use of our core solutions, implementation services, and customer support. Access and use of our core solutions and implementation services are considered distinct.

The transaction price is allocated to each performance obligation on a relative standalone selling price basis. Judgment is required to determine the standalone selling price for each distinct performance obligation. We typically have more than one standalone selling price for individual products and services due to the stratification of those products and services by customers and circumstances. In these instances, we determine the standalone selling price based on our overall pricing objectives, taking into consideration customer demographics and other factors. Fees are fixed based on rates specified in the subscription agreements, which do not provide for any refunds or adjustments.

Deferred Revenues

We record deferred revenues when cash payments are received in advance of our performance. During the year ended December 31, 2018, we recognized $7.1 million of revenues that were included in the deferred revenue balance at the beginning of the period.

Our payment terms vary by the type of our customer and the products or services offered. The time between invoicing and when payment is due is not significant. In instances where the timing of revenue recognition differs from the timing of invoicing, we have determined that our contracts do not include a significant financing component.

Practical Expedients

In determining the transaction price, we have applied the practical expedient which allows us not to adjust the consideration for the effects of the time value of money as long as the time between when we transfer the promised service to a customer and when a customer pays is one year or less.

We do not disclose the value of unsatisfied performance obligations for contracts with an original expected term of one year or less.

We recognize revenue in proportion to the amount we have the right to invoice for certain core solutions and Value+ services revenue, as that amount corresponds directly with our performance completed to date.

Deferred Costs

Deferred costs, which primarily consist of sales commissions, are considered incremental and recoverable costs of obtaining a contract with a customer. These costs are deferred and then amortized on a straight-line basis over a period of benefit that we have determined to be three years. We typically do not pay commissions for contract renewals. We determined the period of benefit by taking into consideration our customer contract term, the useful life of our internal-use software, average customer life, and other factors. Amortization expense for the deferred costs is allocated based on the employee's department and included within cost of revenue and sales and marketing expense in the accompanying Consolidated Statements of Operations. Prior to the adoption of ASU 2014-09, our commissions were expensed as incurred.

Deferred costs were $7.2 million at December 31, 2018, of which $3.2 million is included in prepaid expenses and other current assets and $4.0 million is included in other assets in the accompanying Consolidated Balance Sheets. Amortization expense for deferred costs was $2.0 million for the year ended December 31, 2018. For the year ended December 31, 2018, no impairments were identified in relation to the costs capitalized for the period presented.

Cost of Revenue

Cost of revenue consists of fees paid to third-party service providers associated with delivering certain of our Value+ services (including legal fees and costs associated with the delivery and provision of those services, as well as loss reserves and other costs associated with our legal liability to landlord insurance services), personnel-related costs (including salaries, incentive-based compensation, benefits, and stock-based compensation) for our employees focused on customer service and the support of our operations, platform infrastructure costs (such as data center operations and hosting-related costs), payment processing fees, and allocated shared costs. We typically allocate shared costs across our organization based on headcount within the applicable part of our organization. Cost of revenue excludes depreciation of property and equipment, and amortization of capitalized software development costs and intangible assets.

Sales and Marketing

Sales and marketing expense consists of personnel-related costs (including salaries, sales commissions, incentive-based compensation, benefits, and stock-based compensation) for our employees focused on sales and marketing, costs associated with sales and marketing activities, and allocated shared costs. Marketing activities include advertising, online lead generation, lead nurturing, customer and industry events, and the creation of industry-related content and collateral. Beginning January 1, 2018, due to the adoption of ASU No. 2014-09, Revenue from Contracts with Customers, or ASU 2014-09, sales commissions and other incremental costs to acquire customers and grow adoption and utilization of our Value+ services by our new and existing customers are deferred and then amortized on a straight-line basis over a period of benefit that we have determined to be three years. We focus our sales and marketing efforts on generating awareness of our software solutions, creating sales leads, establishing and promoting our brands, and cultivating an educated community of successful and vocal customers. Advertising expenses were $4.5 million, $3.6 million and $3.6 million for each of the years ended December 31, 2018, 2017 and 2016, respectively, and are expensed as incurred.

Research and Product Development

Research and product development expense consists of personnel-related costs (including salaries, incentive-based compensation, benefits, and stock-based compensation) for our employees focused on research and product development, fees for third-party development resources, and allocated shared costs. Our research and product development efforts are focused on enhancing the ease of use and functionality of our existing software solutions by adding new core functionality, Value+ services and other improvements, as well as developing new products and services. We capitalize the portion of our software development costs that meets the criteria for capitalization. Amortization of capitalized software development costs is included in depreciation and amortization expense.

General and Administrative

General and administrative expense consists of personnel-related costs (including salaries, a majority of total incentive-based compensation, benefits, and stock-based compensation) for employees in our executive, finance, information technology, human resources, corporate development, legal and administrative organizations. In addition, general and administrative expense includes fees for third-party professional services (including audit, legal, tax, and consulting services), transaction costs related to business combinations, other corporate expenses, and allocated shared costs.

Depreciation and Amortization

Depreciation and amortization expense includes depreciation of property and equipment, amortization of capitalized software development costs and amortization of intangible assets. We depreciate or amortize property and equipment, software development costs and intangible assets over their expected useful lives on a straight-line basis, which approximates the pattern in which the economic benefits of the assets are consumed.

Stock-Based Compensation

We recognize stock-based compensation expense for stock-based awards granted to employees and directors that can be settled in shares of our common stock. We estimate the fair value of stock options and performance-based stock options, or PSOs, using the Black-Scholes option-pricing model. We estimate the fair value of RSAs, RSUs and performance-based RSUs or PSU's based on the fair value of our common stock on the date of grant.

Stock Options

For the year ended December 31, 2018, we did not grant time-based stock option or PSOs.

For the years ended December 31, 2017 and 2016, we determined the fair value of awards using the Black-Scholes option-pricing model which requires the use of subjective assumptions. Key assumptions used in this model were (1) the fair value of the underlying ordinary shares, (2) the time period for which we expect the options will be outstanding (the expected term), (3) the expected volatility of our stock price, (4) the risk-free interest rate, and (5) the expected dividend yield. Expected term and expected volatility are the judgments that we believe are subjective in estimating fair value (and related share-based compensation expense) of our option awards.

For the years ended December 31, 2017 and 2016, the expected term was determined using the simplified method, which is calculated as the midpoint of the stock option vesting term and the expiration date of the stock option. We considered historical average volatilities of publicly traded industry peers, in estimating expected volatility for options. Other assumptions used include risk-free interest rate and expected dividend yield. The risk-free interest rate is based on the yield for a U.S. Treasury security having a maturity similar to the expected term of the related option grant. This assumption was dependent on the assumed expected term. The dividend yield of 0% is based on us not paying or anticipating paying any cash dividends in the foreseeable future.

Restricted Stock Units

RSUs vest in equal tranches over four annual periods and are expensed on a straight-line basis over the vesting period. The shares underlying the RSU grants are not issued and outstanding until the applicable vesting date.

Performance-Based Equity Awards

Our PSOs and PSUs, include performance conditions that require us to estimate the probable outcome of the performance condition. This assessment is based on management's judgment using internally developed forecasts and assessed at each reporting period. Compensation cost is recorded if it is probable that the performance condition will be achieved. Adjustments to compensation expense are made each period based on changes in our estimate of the number of PSOs and PSUs that are probable of vesting. PSOs and PSUs will vest upon achievement of the relevant performance metric once such calculation is reviewed and approved by our board of directors.

Forfeiture Rate

We estimate a forfeiture rate to calculate our stock-based compensation expense for our stock-based awards. The forfeiture rate is based on an analysis of actual forfeitures. We will continue to evaluate the appropriateness of the forfeiture rate based on actual forfeiture experience, analysis of employee turnover, and other factors. Changes in the estimated forfeiture rate can have a significant impact on our stock-based compensation expense as the cumulative effect of adjusting the rate is recognized in the period the estimated forfeiture rate is changed. If a revised forfeiture rate is higher than the previously-estimated forfeiture rate, an adjustment is made that will result in a decrease to our stock-based compensation expense recognized in our Consolidated Financial Statements. If a revised forfeiture rate is lower than the previously-estimated forfeiture rate, an adjustment is made that will result in an increase to our stock-based compensation expense recognized in our Consolidated Financial Statements.

Income Taxes

We recognize deferred tax liabilities and assets for the expected future tax consequences of temporary differences between the carrying amounts and the tax bases of assets and liabilities. Deferred income tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in the Consolidated Statements of Operations in the period that includes the enactment date. A valuation allowance is recorded when it is more likely than not that some of the deferred tax assets will not be realized.

We recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in our Consolidated Financial Statements from such positions are then measured based on the largest benefit that has a greater than 50% likelihood of being realized. We recognize interest and penalties accrued with respect to uncertain tax positions, if any, in our provision for income taxes in the Consolidated Statements of Operations.

Net Income (Loss) per Share

Basic net income (loss) per share includes no dilution and is computed by dividing net income (loss) for the period by the weighted average number of common shares outstanding during the period. Diluted net income (loss) per share is computed by dividing net income (loss) for the period by the weighted average number of shares of common stock and potentially dilutive common stock outstanding during the period. The dilutive effect of outstanding options and equity incentive awards is reflected in diluted net income (loss) per share by application of the treasury stock method. The calculation of diluted net income (loss) per share excludes all anti-dilutive common shares.

The net income (loss) per common share was the same for our Class A and Class B common shares because they are entitled to the same liquidation and dividend rights and are therefore combined in the table below. The following table presents a reconciliation of our weighted average number of Class A and Class B common shares used to compute net income (loss) per share (in thousands):



	Year Ended December 31,
	2018	2017	2016
Weighted average common shares outstanding	34,139	33,876	33,639
Less: Weighted average unvested restricted shares subject to repurchase	11	27	78
Weighted average common shares outstanding; basic	34,128	33,849	33,561

Weighted average common shares outstanding; basic	34,128	33,849	33,561
Plus: Weighted average options, restricted stock units and restricted shares used to compute diluted net income per common share	1,434	1,302	—
Weighted average common shares outstanding; diluted	35,562	35,151	33,561

Approximately 358,000 and 548,000 shares of PSOs and PSUs are not included in the computations of diluted and anti-dilutive shares for the years ended December 31, 2018 and 2017, respectively, as they are considered contingently issuable upon the satisfaction of pre-defined performance measures and their respective performance measures have not been met.

For the year ended December 31, 2016, we reported a net loss and therefore all potentially dilutive common shares are anti-dilutive and have been excluded from the calculation of net loss per share. The following table presents the number of anti-dilutive common shares excluded from the calculation of weighted average number of shares used to compute diluted net income (loss) per share for the years ended December 31, 2018, 2017 and 2016 (in thousands):



	December 31,
	2018	2017	2016
Options to purchase common stock	—	—	1,718
Unvested RSAs	—	—	46
Unvested restricted stock units	10	21	496
Contingent restricted stock units⁽¹⁾	—	6	34
Total shares excluded from diluted net income per common share	10	27	2,294

⁽¹⁾The reported shares are based on fixed price RSU commitments for which the number of shares has not been determined at the grant date. The number of shares have been determined by dividing the fixed price commitment to issue shares in the future by the closing price of our common stock at the applicable reporting period date.

Recently Adopted Accounting Pronouncements

In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, as amended, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers (the “New Revenue Standard”). The New Revenue Standard also includes Subtopic 340-40, Other Assets and Deferred Costs - Contracts with Customers, which discusses the deferral of incremental costs of obtaining a contract with a customer.

We adopted the New Revenue Standard at January 1, 2018 using the modified retrospective transition method applied to those contracts which were not completed at that date. We recognized the cumulative effect of initially applying the New Revenue Standard as an adjustment to the opening balance of retained earnings. The comparative information has not been recast and continues to be reported under the accounting standards in effect for those periods. We updated our accounting policies, processes, internal controls and information systems to conform to the New Revenue Standard's reporting and disclosure requirements.

The adoption of the New Revenue Standard did not have an impact on our revenues. It did, however, have a significant impact related to the deferral of incremental costs of obtaining contracts. Prior to the adoption of the New Revenue Standard, our commissions were expensed as incurred.

The cumulative effects of the changes made to our Consolidated Balance Sheet at January 1, 2018 for the adoption of the New Revenue Standard were as follows (in thousands):



	Balance at December 31, 2017			Adjustments		Balance at January 1, 2018
Assets
Prepaid expenses and other current assets	$	4,546		$	1,148	$	5,694
Other assets	1,238			1,816		3,054

Equity
Accumulated deficit	$	(67,247	)	$	2,964	$	(64,283	)

The following tables presents the current period impacts of adopting the New Revenue Standard on our Consolidated Financial Statements (in thousands):

Consolidated Balance Sheet:



	December 31, 2018
	As Reported			Balances Without Adoption of ASU 2014-09			Effect of Adoption
Assets
Prepaid expenses and other current assets	$	11,775		$	8,548		$	3,227
Other assets	7,688			3,709			3,979

Equity
Accumulated deficit	$	(44,316	)	$	(51,522	)	$	7,206

Consolidated Statements of Operations:



	Year Ended December 31, 2018
	As Reported		Balances Without Adoption of ASU 2014-09		Effect of Adoption
Costs and operating expenses:
Cost of revenue (exclusive of depreciation and amortization)	$	73,549	$	73,786	$	(237	)
Sales and marketing	33,288		37,295		(4,007		)
Total costs and operating expenses	170,415		174,659		(4,244		)
Income from operations	19,656		15,412		4,244
Income before provision for income taxes	20,387		16,143		4,244
Net income	$	19,967	$	15,723	$	4,244

Net income per common share:
Basic	$	0.59	$	0.46	$	0.13
Diluted	$	0.56	$	0.44	$	0.12

In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments ("ASU 2016-15"), which provides cash flow statement classification guidance for debt prepayment or debt extinguishment costs; settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies; distributions received from equity method investees; beneficial interests in securitization transactions; and separately identifiable cash flows and application of the predominance principle. We adopted ASU 2016-15 effective January 1, 2018. The adoption of this guidance did not have a material impact on our statements of cash flows.

In October 2016, the FASB issued ASU No. 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory ("ASU 2016-16"), which changes the timing of when certain intercompany transactions are recognized within the provision for income taxes. We adopted ASU 2016-16 effective January 1, 2018. The adoption of this guidance did not have a material impact on our financial condition, results of operations, cash flows or disclosures.

In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash ("ASU 2016-18"), which provides amendments to current guidance to address the classification and presentation of changes in restricted cash in the statement of cash flows. We adopted ASU 2016-18 effective January 1, 2018. The adoption of this guidance changed the presentation of restricted cash on our statements of cash flows.

In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment ("ASU 2017-04"), which eliminates Step 2 from the goodwill impairment test. The annual, or interim goodwill impairment test is performed by comparing the fair value of a reporting unit with its carrying amount. An impairment charge should be recognized for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. In addition, income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit should be considered when measuring the goodwill impairment loss, if applicable. ASU 2017-04 also eliminates the requirements for any reporting unit with a zero or negative carrying amount to perform a qualitative assessment and, if it fails that qualitative test, to perform Step 2 of the goodwill impairment test. An entity still has the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. ASU 2017-04 is effective for public entities for fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on dates after January 1, 2017. We early adopted ASU 2017-04 effective January 1, 2018. The adoption of this guidance did not have a material impact on our financial condition, results of operations, cash flows or disclosures.

In May 2017, the FASB issued ASU No. 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting ("ASU 2017-09"). ASU 2017-09 clarifies when changes to the terms or conditions of a share-based payment award must be accounted for as modifications. The new guidance will reduce diversity in practice and result in fewer changes to the terms of an award being accounted for as modifications. Under ASU 2017-09, an entity will not apply modification accounting to a share-based payment award if the award’s fair value, vesting conditions and classification as an equity or liability instrument are the same immediately before and after the change. ASU 2017-09 will be applied prospectively to awards modified on or after the adoption date. We adopted ASU 2017-09 effective January 1, 2018. The adoption of this guidance did not have a material impact on our financial condition, results of operations, cash flows or disclosures.

In January 2017, the FASB issued ASU No. 2017-01, Business Combinations - Clarifying the Definition of a Business (Topic 805), which clarifies the definition of a business for determining whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The Company adopted this standard on January 1, 2018 and is applying the standard prospectively to determine whether certain future transactions should be accounted for as acquisitions of assets or businesses.

Recent Accounting Pronouncements Not Yet Adopted

In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) ("ASU 2016-02"), an entity will be required to recognize right-of-use assets and lease liabilities on its balance sheet and disclose key information about leasing arrangements. ASU 2016-02 offers specific accounting guidance for a lessee, a lessor and sale and leaseback transactions. Lessees and lessors are required to disclose qualitative and quantitative information about leasing arrangements to enable a user of the financial statements to assess the amount, timing and uncertainty of cash flows arising from leases. For public companies, ASU 2016-02 is effective for annual reporting periods beginning after December 15, 2018, including interim periods within that reporting period. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted Improvements ("ASU 2018-11"). Among other things, ASU 2018-11 provides administrative relief by allowing entities to implement the lease standard on a modified retrospective basis ("The Optional Transition Method"), similar to the method that we used to adopt the new revenue standard. Effectively, The Optional Transition Method permits us to adopt the lease standard through a cumulative effect adjustment to our opening balance sheet for the first quarter of fiscal year 2019, with the cumulative effect accounted for as a component of retained earnings, and report under the new lease standard on a post adoption basis. We will adopt the new standard effective January 1, 2019 using The Optional Transition Method and will not recast comparative periods. We will elect the package of practical expedients permitted under the transition guidance, which allows us to carry forward our historical lease classification, our assessment on whether a contract is or contains a lease, and our initial direct costs for any leases that exist prior to adoption of the new standard. We will also elect to combine lease and non-lease components and to keep leases with an initial term of 12 months or less off the balance sheet and recognize the associated lease payments in the Consolidated Statements of Operations on a straight-line basis over the lease term. We are currently in the process of determining the impact that this ASU will have on our Consolidated Financial Statements. We believe the impact will result in adding material lease assets and liabilities to our Consolidated Balance Sheet. At December 31, 2018, our total undiscounted minimum payments under our operating leases amounted to $27.0 million.

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments ("ASU 2016-13"), which amends the current accounting guidance and requires the measurement of all expected losses based on historical experience, current conditions and reasonable and supportable forecasts. This guidance amends the accounting for credit losses for available-for-sale investment securities and purchased financial assets with credit deterioration. ASU 2016-13 is effective for annual periods beginning after December 15, 2019, and interim periods within those annual periods. Early adoption is permitted for any interim or annual period after December 15, 2018. We are currently evaluating the effect of the adoption of ASU 2016-13 on our Consolidated Financial Statements. The effect will largely depend on the composition and credit quality of our investment portfolio and the economic conditions at the time of adoption.

In March 2017, the FASB issued ASU No. 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities (“ASU 2017-08”). ASU 2017-08 shortens the amortization period for certain callable debt securities held at a premium. Specifically, ASU 2017-08 requires the premium to be amortized to the earliest call date. ASU 2017-08 does not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. For public companies, ASU 2017-08 is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted, including adoption in an interim period. The amendments should be applied on a modified retrospective basis, with a cumulative-effect adjustment directly to retained earnings at the beginning of the period of adoption. We do not expect the adoption of this guidance to have a material impact on our financial condition, results of operations, cash flows or disclosures since our current accounting policy is consistent with ASU 2017-08.

In June 2018, the FASB issued ASU No. 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting ("ASU 2018-07"). This amendment expands the scope of Topic 718, Compensation—Stock Compensation (which only included share-based payments to employees) to include share-based payments issued to nonemployees for goods or services. Consequently, the accounting for share-based payments to nonemployees and employees will be substantially aligned. ASU 2018-07 supersedes Subtopic 505-50, Equity—Equity-Based Payments to Non-Employees and is effective for annual reporting periods, and interim periods within those annual periods, beginning after December 15, 2018. We do not expect the adoption of this guidance to have a material impact on our financial condition, results of operations, cash flows or disclosures.

In August 2018, the FASB issued ASU No. 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract, a series of amendments which align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). The accounting for the service element of a hosting arrangement that is a service contract is not affected by these amendments. For public business entities, the amendments are effective for annual periods, including interim periods within those annual periods, beginning after December 15, 2019. We have not yet determined the effect of this guidance on our financial condition, results of operations, cash flows or disclosures.

Acquisition of WegoWise

12 Months Ended

Dec. 31, 2018

Business Combinations [Abstract]

Acquisition of WegoWise

On August 31, 2018, we completed the acquisition of substantially all of the assets of WegoWise, a provider of cloud-based utility analytics software solutions serving the real estate market. The WegoWise platform empowers building owners and third-party property managers to better manage operating and capital expenditures relating to utilities, and we expect that the acquisition will provide enhanced functionality to our real estate customers over time, such as a future utility analytics and management Value+ services.

The consideration paid in cash for the assets was $14.4 million, of which $2.0 million will be held in escrow for twelve months to satisfy WegoWise’s indemnity obligations. In addition, if during the period beginning immediately after the closing of the transaction (the "Closing") and ending on the six month anniversary of the Closing, we enter into contracts with certain third parties (each, a "Milestone Contract"), we will be obligated to pay to WegoWise the aggregate amount of the recurring revenues billed and collected from the Milestone Contract that results in the highest amount of recurring revenues billed during the twelve month period ("Determination Period") following the date recurring revenue is first billed for such Milestone Contract, but in no event will the Determination Period extend beyond the date which is the 15th month anniversary of the execution of the Milestone Contract (and we will not be obligated to pay WegoWise for any recurring revenues resulting from any other Milestone Contracts).

Subsequent to the acquisition date we have become aware that the Milestone Contracts will not be executed prior to the six month anniversary of February 28, 2019. As the fair value was not material and no liability was recorded at the acquisition date, there is no change in fair value recorded at December 31, 2018.

The transaction was accounted for using the acquisition method, and as a result, assets acquired, and liabilities assumed were recorded at their estimated fair values at the acquisition date. The fair values were based on management's analysis as well as work performed by third-party valuation specialists. The following table presents the purchase price allocation (in thousands) as well as the useful lives of the acquired intangible assets over which they are amortized on a straight-line basis, as this approximates the pattern in which economic benefits of the assets are consumed:



	Amount (in thousands)		Estimated Useful Life (in years)
Net tangible assets	$	270
Identified intangible assets:
Customer relationships	1,170		5.0
Database	3,620		10.0
Trademark and trade name	370		10.0
Non-compete agreement	60		5.0
Backlog	140		1.0
Total intangible assets subject to amortization	5,360		8.6
Goodwill	8,811		Indefinite
Purchase consideration, paid in cash	$	14,441

Goodwill is mainly attributable to synergies expected from the acquisition and assembled workforce and is deductible for U.S. federal income tax purposes.

We incurred a total of $240,000 in transaction costs related to the acquisition and expensed all transaction costs incurred during the period in which such service was received. The results of operations of WegoWise since the acquisition are included in our Consolidated Statements of Operations for the year ended December 31, 2018. Revenue and net loss attributable to WegoWise, in the period from the acquisition date of August 31, 2018 through December 31, 2018, were $0.4 million and $(1.4) million, respectively.

The following unaudited pro forma information has been prepared for illustrative purposes only, assumes that the acquisition occurred on January 1, 2017 and includes pro forma adjustments related to the amortization of acquired intangible assets, elimination of historical interest expense on WegoWise debt, which was paid off as part of the transaction, and the transaction costs incurred. The unaudited pro forma results have been prepared based on estimates and assumptions, which we believe are reasonable; however, they are not necessarily indicative of the consolidated results of operations had the acquisition occurred on January 1, 2017, or of future results of operations. The unaudited pro forma results are as follows (in thousands, except per share amounts):



	Year Ended December 31,
	2018		2017
Revenue	$	192,523	$	146,859
Net income	$	18,247	$	5,052

Net income per common share:
Basic	$	0.53	$	0.15
Diluted	$	0.51	$	0.14

Investment Securities and Fair Value Measurements

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Investment Securities and Fair Value Measurements

Investment Securities

Investment securities classified as available-for-sale consisted of the following at December 31, 2018 and 2017 (in thousands):



	December 31, 2018
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Corporate bonds	$	23,720	$	—	$	(163	)	$	23,557
Agency securities	4,345		4		(19		)	4,330
Total available-for-sale investment securities	$	28,065	$	4	$	(182	)	$	27,887



	December 31, 2017
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Corporate bonds	$	38,383	$	—	$	(166	)	$	38,217
Agency securities	11,045		—		(42		)	11,003
Certificates of deposit	2,982		1		(2		)	2,981
Total available-for-sale investment securities	$	52,410	$	1	$	(210	)	$	52,201

At December 31, 2018, the unrealized losses on investment securities which have been in a net loss position for twelve months or greater were not material. These unrealized losses are considered temporary and there were no impairments considered to be "other-than-temporary" based on our evaluation of available evidence, which includes our intent to hold these investments to maturity or a recovery of the cost basis.

At December 31, 2018 and 2017, the contractual maturities of our investments did not exceed 36 months. The fair values of available-for-sale investments, by remaining contractual maturity, are as follows (in thousands):



	December 31, 2018				December 31, 2017
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Due in one year or less	$	16,738	$	16,631	$	29,850	$	29,800
Due after one year through three years	11,327		11,256		22,560		22,401
Total available-for-sale investment securities	$	28,065	$	27,887	$	52,410	$	52,201

During the years ended December 31, 2018 and 2017, we had sales and maturities (which include calls) of investment securities, as follows (in thousands):



	Year Ended December 31, 2018
	Gross Realized Gains		Gross Realized Losses			Gross Proceeds from Sales			Gross Proceeds from Maturities
Corporate bonds	$	—	$	(11	)	$	(6,624	)	$	(19,307	)
Agency securities	4		(14		)	(5,671		)	(7,000		)
Certificates of deposit	—		—			—			(2,982		)
Treasury securities	—		(10		)	(8,605		)	(3,530		)
	$	4	$	(35	)	$	(20,900	)	$	(32,819	)



	Year Ended December 31, 2017
	Gross Realized Gains		Gross Realized Losses		Gross Proceeds from Sales		Gross Proceeds from Maturities
Agency securities	$	1	$	—	$	15	$	3,294
Corporate bonds	—		—		—		10,690
Certificates of deposit	—		—		—		2,490
	$	1	$	—	$	15	$	16,474

For the years ended December 31, 2018, 2017 and 2016 we received interest income net of the amortization and accretion of the premium and discount of $1.0 million, $0.7 million, and $0.5 million, respectively.

Fair Value Measurements

Recurring Fair Value Measurements

Financial assets and financial liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The following tables presents our financial assets and liabilities measured at fair value on a recurring basis at December 31, 2018 and 2017, by level within the fair value hierarchy (in thousands):



	December 31, 2018
	Level 1		Level 2		Level 3		Total Fair Value
Cash equivalents:
Money market funds	$	10,694	$	—	$	—	$	10,694
Available-for-sale investment securities:
Corporate bonds	—		23,557		—		23,557
Agency securities	—		4,330		—		4,330
Total	$	10,694	$	27,887	$	—	$	38,581



	December 31, 2017
	Level 1		Level 2		Level 3		Total Fair Value
Cash equivalents:
Money market funds	$	5,524	$	—	$	—	$	5,524
Available-for-sale investment securities:
Corporate bonds	—		38,217		—		38,217
Agency securities	—		11,003		—		11,003
Certificates of deposit	2,981		—		—		2,981
Total Assets	$	8,505	$	49,220	$	—	$	57,725

The carrying amounts of cash equivalents, restricted cash, accounts receivable, accounts payable and accrued liabilities approximate fair value because of the short maturity of these items.

There were no changes to our valuation techniques used to measure asset and liability fair values on a recurring basis during the year ended December 31, 2018. The valuation techniques for the items in the table above are as follows:

Cash Equivalents

At December 31, 2018 and 2017, cash equivalents include cash invested in money market funds. Fair value is based on market prices for identical assets.

Available-for-Sale Investment Securities

Our Level 2 securities were priced by a pricing vendor. The pricing vendor utilizes the most recent observable market information in pricing these securities or, if specific prices are not available for these securities, use of other observable inputs like market transactions involving comparable securities. The fair value of our certificates of deposit is based on market prices for identical assets.

Non-Recurring Fair Value Measurements

Certain assets, including goodwill, intangible assets and our note receivable with SecureDocs, are also subject to measurement at fair value on a non-recurring basis using Level 3 measurement, but only when they are deemed to be impaired as a result of an impairment review. For the years ended December 31, 2018, 2017 and 2016, no impairments were identified on those assets required to be measured at fair value on a non-recurring basis.

Property and Equipment

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

Property and Equipment

Property and equipment consists of the following at December 31, 2018 and 2017 (in thousands):



	December 31,
	2018			2017
Data center and computer equipment	$	6,854		$	5,233
Furniture and fixtures	2,928			2,415
Office equipment	798			763
Leasehold improvements	5,254			5,029
Construction in process	79			—
Gross property and equipment	15,913			13,440
Less: Accumulated depreciation	(9,042		)	(6,744		)
Total property and equipment, net	$	6,871		$	6,696

Depreciation expense for property and equipment totaled $2.4 million, $2.3 million, and $2.3 million for the years ended December 31, 2018, 2017 and 2016, respectively.

Internal-Use Software Development Costs

12 Months Ended

Dec. 31, 2018

Research and Development [Abstract]

Internal-Use Software Development Costs

Internal-use software development costs were as follows (in thousands):



	December 31,
	2018			2017
Internal use software development costs, gross	$	58,237		$	44,626
Less: Accumulated amortization	(37,752		)	(27,017		)
Internal use software development costs, net	$	20,485		$	17,609

Capitalized software development costs were $13.8 million, $11.1 million and $11.8 million for the years ended December 31, 2018, 2017 and 2016, respectively. Amortization expense with respect to software development costs totaled $11.0 million, $9.0 million and $6.2 million for the years ended December 31, 2018, 2017 and 2016, respectively.

Future amortization expense with respect to capitalized software development costs at December 31, 2018 is estimated as follows (in thousands):



Years Ending December 31,
2019	$	10,664
2020	6,848
2021	2,950
2022	23
Total amortization expense	$	20,485

Goodwill and Intangible Assets

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Intangible Assets

Intangible Assets

The change in the carrying amount of goodwill is as follows (in thousands):



Goodwill at December 31, 2017	$	6,737
Goodwill from acquisition of WegoWise	8,811
Goodwill at December 31, 2018	$	15,548

Intangible assets consisted of the following at December 31, 2018 and 2017 (in thousands, except years):



	December 31, 2018
	Gross Carrying Value		Accumulated Amortization			Net Carrying Value		Weighted Average Useful Life in Years
Customer relationships	$	1,960	$	(728	)	$	1,232	5.0
Database	3,620		(121		)	3,499		10.0
Technology	4,811		(4,506		)	305		8.0
Trademarks and trade names	1,300		(642		)	658		9.0
Partner relationships	680		(680		)	—		3.0
Non-compete agreements	100		(44		)	56		4.0
Domain names	273		(273		)	—		5.0
Patents	285		(233		)	52		5.0
Backlog	140		(47		)	93		1.0
	$	13,169	$	(7,274	)	$	5,895	7.0



	December 31, 2017
	Gross Carrying Value		Accumulated Amortization			Net Carrying Value		Weighted Average Useful Life in Years
Customer relationships	$	790	$	(538	)	$	252	5.0
Technology	4,811		(3,871		)	940		6.0
Trademarks	930		(539		)	391		9.0
Partner relationships	680		(623		)	57		3.0
Non-compete agreements	40		(37		)	3		3.0
Domain names	273		(273		)	—		5.0
Patents	285		(203		)	82		5.0
	$	7,809	$	(6,084	)	$	1,725	5.9

Amortization expense totaled $1.2 million, $1.4 million and $1.4 million for the years ended December 31, 2018, 2017 and 2016, respectively. Amortization expense for each of the five fiscal years through December 31, 2023 is estimated as follows (in thousands):



Years Ending December 31,
2019	$	1,091
2020	904
2021	769
2022	706
2023	563
Thereafter	1,862
Total amortization expense	$	5,895

Long-term Debt

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Long-term Debt

The following is a summary of our long-term debt at December 31, 2018 (in thousands):



Principal amounts due under term loan	$	50,000
Less: Debt financing costs	(185		)
Long-term debt, net of unamortized debt financing costs	49,815
Less: Current portion of long-term debt	(1,213		)
Total long-term debt, net of current portion	48,602

Scheduled principal payments for the Term Loan at December 31, 2018 are as follows (in thousands):



Years Ending December 31,
2019		1,250
2020		1,250
2021		2,500
2022		2,500
2023		42,500
Total principal payments		50,000

Credit Agreement

On March 16, 2015, we entered into a credit facility (the “Original Credit Agreement” and as amended, the "Credit Agreement") comprised of a $10.0 million term loan (the “Original Term Loan”), and a $2.5 million revolving line of credit (the "Original Revolving Facility") with Wells Fargo, as administrative agent, and the lenders that are parties thereto ("Wells Fargo"). In March 2015, we borrowed $10.0 million under the Original Term Loan and on July 16, 2015, we made an optional prepayment in full of the Original Term Loan.

First Amendment to Credit Agreement

On October 9, 2015, we entered into Amendment Number One to the Original Credit Agreement (the "First Amendment"), which amended the terms of the Original Credit Agreement with Wells Fargo.

Under the terms of the Credit Agreement, the lenders made available to us a $25.0 million revolving line of credit (the “Revolving Facility”). Subject to customary terms and conditions, we can seek to increase the principal amount of indebtedness available under the First Amendment by up to $10.0 million, in the form of revolving commitments or term loan debt, although the lenders are under no obligation to make additional amounts available to us. Borrowings under the Revolving Facility are subject to the satisfaction of customary conditions.

Under the terms of the First Amendment, borrowings under the Revolving Facility bear interest at a fluctuating rate per annum equal to, at our option, (i) a base rate equal to the highest of (a) the federal funds rate plus 1/2 of 1%, (b) the London Interbank Offered Rate (“LIBOR”) for a one-month interest period plus 1% and (c) the rate of interest in effect for such day as publicly announced from time to time by Wells Fargo as its prime rate, in each case plus an applicable margin of 1.5%, or (ii) LIBOR for the applicable interest period plus an applicable margin of 2.5%. Interest is due and payable monthly. We are also required to pay a commitment fee equal to 0.25% per annum of the unused portion of the Revolving Facility if revolver usage is above $10.0 million, or 0.375% per annum of the unused portion of the Revolving Facility if revolver usage is less than or equal to $10.0 million.

In conjunction with the First Amendment, during 2015 we incurred and capitalized deferred financing costs of $0.2 million. These additional costs were added to the unamortized debt financing costs from the Original Revolving Facility of $0.1 million, amortized using a straight-line method over the term of the Revolving Facility's commitment and included in interest expense in the Consolidated Statements of Operations.

Second Amendment to Credit Agreement

On December 24, 2018, we entered into Amendment Number Two to the Credit Agreement (the "Second Amendment"), which amended the terms of the Original Credit Agreement, as amended by the First Amendment.

Under the terms of the Second Amendment, the lenders have made available to us a $50.0 million term loan (the "Term Loan") and have increased the existing $25.0 million Revolving Facility to $50.0 million. The maturity date of the Term Loan and Revolving Facility is December 24, 2023. In addition, we are now permitted to make certain restricted junior payments, including without limitation stock repurchases and enter into acquisitions in which we are the purchaser ("Acquisitions"), with no dollar cap on such Acquisitions, so long as we maintain certain specified liquidity requirements and leverage ratios.

The Second Amendment also modifies certain financial covenants by, among other things, requiring us to maintain (i) an EBITDA to interest expense ratio of not less than 3.0 to 1.0, and (ii) a funded indebtedness to EBITDA ratio of not more than 3.5:1.0 (the "Required Leverage Ratio") (decreasing by 0.25 per year until the Required Leverage Ratio is 2.5 to 1.0); provided, however, that we are not required to maintain the foregoing ratios if our liquidity (sum of remaining borrowing capacity and available cash) has equaled or exceeded the greater of $20.0 million and 20% of the sum of the outstanding principal amount of the Term Loan and commitments under the Revolving Facility. If we enter into an Acquisition with a purchase price greater than or equal to $20.0 million, then the Required Leverage Ratio will be increased by 0.5 for the 12-month period immediately following the consummation of such Acquisition.

The Credit Agreement contains customary affirmative, negative and financial covenants. The affirmative covenants require us to, among other things, disclose financial and other information to the lenders, maintain our business and properties, and maintain adequate insurance. The negative covenants restrict us from, among other things, incurring additional indebtedness, prepaying certain types of indebtedness, encumbering or disposing of our assets, making fundamental changes to our corporate structure, and making certain dividends and distributions. At December 31, 2018, we were in compliance with the financial covenants under the Credit Agreement.

Under the terms of the Second Amendment, borrowings under the Credit Agreement will bear interest at a fluctuating rate per annum equal to, at our option, (i) the adjusted London Interbank Offered Rate ("LIBOR") or (ii) an alternate base rate, in each case plus the applicable interest rate margin. Borrowings will initially bear interest at adjusted LIBOR plus 2.0% per annum, in the case of LIBOR borrowings, or at the alternate base rate plus 1.0% per annum. After a compliance certificate has been delivered to Wells Fargo by us for the quarter ending December 31, 2018, the interest rate will fluctuate between adjusted LIBOR plus 1.5% per annum and adjusted LIBOR plus 2.0% per annum (or between the alternate base rate plus 0.5% per annum and the alternate base rate plus 1.0% per annum), based upon our leverage ratio.

Fees payable on the unused portion of the Revolving Facility will be 25 basis points per annum, unless the average usage of the Revolving Facility is equal to or less than $30.0 million for the applicable period, in which case the fees on the unused portion of the Revolving Facility will be 0.375% per annum.

At December 31, 2018 and 2017, there was no outstanding balance under the Revolving Facility.

The estimated fair value of the Term Loan approximates its carrying value due to the short period from the date of the Second Amendment, December 24, 2018, to the reporting period, December 31, 2018. We consider the fair value of the Term Loan to be a Level 2 measurement as the Term Loan is not actively traded. We carry the Term Loan at face value less the unamortized discount on our Consolidated Balance Sheet.

As a result of the Second Amendment, we incurred $0.4 million in financing fees that were capitalized and will be amortized over the remaining life of the related debt, $0.2 million of which was related to the Term Loan and $0.2 million of which was related to the Revolving Facility. Pursuant to GAAP, the Second Amendment is accounted for as a debt modification. As a result, the unamortized deferred debt financing costs related to the Revolving Facility prior to the Second Amendment were added to the $0.2 million of deferred debt financing costs related to the Second Amendment and will be amortized over the remaining life of the Revolving Facility. The following table presents the total deferred debt financing costs for the term loan and the Revolving Facility (in thousands):



	Term Loan		Revolving Facility
Deferred financing costs at December 31, 2017	$	—	$	175
Deferred financing costs Second Amendment	185		185
Amortization of deferred financing costs	—		(60		)
Deferred financing costs at December 31, 2018	$	185	$	300

Debt Financing Costs

Debt financing costs are deferred and amortized, using the straight-line method, which approximates the effective interest method, for costs related to the Term Loan and the straight-line method for costs related to the Revolving Facility over the term of the debt arrangement; such amortization is included in interest expense in the Consolidated Statements of Operations. Amortization of deferred debt financing costs was not material for the years ended December 31, 2018, 2017 and 2016. At December 31, 2018 and 2017, the remaining unamortized deferred debt financing costs were $0.5 million and $0.2 million, respectively, of which, at December 31, 2018, $0.2 million was offset against debt. At December 31, 2018 and 2017, $0.3 million and $0.2 million of the remaining unamortized deferred debt financing costs were recorded in prepaid expenses and other current assets and other assets on the Consolidated Balance Sheet, respectively, as they pertained to the Revolving Facility.

Commitment and Contingencies

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Lease Obligations

At December 31, 2018, we had operating lease obligations of approximately $27.0 million through 2028. A summary of our future minimum payments for obligations under non-cancellable operating leases is as follows (in thousands):



Years Ending December 31,
2019	$	4,211
2020	4,889
2021	4,038
2022	2,717
2023	2,053
Thereafter	9,128
Total lease commitments	$	27,036

We recorded rent expense of $2.6 million, $2.1 million and $2.0 million for the years ended December 31, 2018, 2017 and 2016, respectively.

On July 27, 2018, we entered into a new lease agreement (the "Lease") with Nassau Land Company, L.P. (the "Landlord"), to lease approximately 86,000 square feet of office space located at 70 Castilian Drive in Santa Barbara, California (the "Premises"), which is directly adjacent to our corporate headquarters.

The term of the Lease is 10 years, beginning on September 1, 2018 (the "Commencement Date"), and ending on the tenth anniversary of the Commencement Date. The term may be extended for two additional five year terms at our election.

Beginning March 1, 2019, we will pay a base rent of approximately $80,000 per month for 60% of the Premises. Beginning March 1, 2020, we will pay a base rent of approximately $107,000 per month for 80% of the Premises. Beginning June 1, 2020, we will pay a base rent of approximately $134,000 per month for 100% of the Premises. The base rent will increase 3% annually, with the first such increase effective on March 1, 2020. The total commitment under this lease is $16.6 million.

On July 27, 2018, we also entered into a lease amendment for 90 Castilian Drive in Santa Barbara, California. This amendment extends the term of the lease from November 2020 to April 2023. The term may be extended for two additional three year terms at our election. The total commitment under this lease extension is $1.8 million. All other terms and conditions from the original lease and previous amendments remain the same.

On September 30, 2018, we entered into a Membership Agreement (the "Membership Agreement") with WeWork to lease office space located at 7300 one Star Drive in Plano, Texas. The term of the Membership Agreement commences on December 1, 2018 and is for a period of 24 months. We pay a fee of $61,000 per month for the leased premises.

Legal Liability to Landlord Insurance

We have a wholly owned subsidiary, Terra Mar Insurance Company, Inc., which was established to provide our customers with the option to purchase legal liability to landlord insurance. If our customers choose to use our insurance services, they are issued an insurance policy underwritten by our third-party service provider. The policy has a limit of $100,000 per incident for each insured residence. We have entered into a reinsurance agreement with our third-party service provider and, as a result, we assume a 100% quota share of the legal liability to landlord insurance provided to our customers through our third-party service provider. Included in cost of revenue we accrue for reported claims, and an estimate of losses incurred but not reported by our property manager customers, as we bear the risk related to claims. Our liability for reported claims and incurred but not reported claims at December 31, 2018 and 2017 was $0.6 million and $0.5 million, respectively, and is included in other current liabilities on the Consolidated Balance Sheets.

Included in prepaid expenses and other current assets at each of December 31, 2018 and 2017 are $1.8 million of deposits held with a third party related to requirements to maintain collateral for our insurance services.

Litigation

In December 2018, we received a Civil Investigative Demand ("CID") from the Federal Trade Commission ("FTC") requesting certain information relating to our compliance with the Fair Credit Reporting Act ("FCRA") in connection with our tenant screening Value+ service. We are fully cooperating with the FTC and are now in the process of responding to the CID. We do not presently have sufficient information to predict the outcome of, or any potential costs or penalties associated with, the investigation.

In September 2017, a putative federal class action styled Leo v. AppFolio, Inc. (Civ. No. 3:17-cv-05771; W.D. Wash.) was filed naming us as a defendant and alleging certain violations of the FCRA in connection with our tenant screening Value+ service (the "Leo Litigation"). The parties reached an agreement to settle the Leo Litigation in the fourth quarter of 2018. The court has approved the proposed settlement on a preliminary basis, and recently directed the parties to provide notice to the classes. We do not, and will not, admit any liability whatsoever in connection with the claims and allegations in the Leo Litigation. The final settlement will be subject to court approval.

As a result of the pending settlement of the Leo Litigation, we recorded an expense, net of expected insurance proceeds, of $1.1 million during the twelve months ended December 31, 2018, within cost of revenue. Our insurer has agreed to pay its portion of the settlement proceeds directly to the settlement fund following final court approval.

In addition, from time to time, we are involved in various other legal proceedings arising from or related to claims incident to the ordinary course of our business activities, including actions with respect to intellectual property, employment and contractual matters. Although the results of such legal proceedings and claims cannot be predicted with certainty, we believe that we are not currently a party to any legal proceeding(s) which, if determined adversely to us, would, individually or taken together, have a material adverse effect on our business, operating results, financial condition or cash flows.

Indemnification

In the ordinary course of business, we may provide indemnification of varying scope and terms to customers, investors, directors and officers with respect to certain matters, including, but not limited to, losses arising out of our breach of any applicable agreements, services to be provided by us, or intellectual property infringement claims made by third parties. These indemnification provisions may survive termination of the underlying agreement and the maximum potential amount of future payments we could be required to make under these indemnification provisions may not be subject to maximum loss clauses and is indeterminable. We have never paid a material claim, nor have any legal claims been brought against us, in connection with these indemnification arrangements. At December 31, 2018 and 2017, we had not accrued a liability for these indemnification arrangements because we determined that the likelihood of incurring a payment obligation, if any, in connection with these indemnification arrangements is not probable or reasonably possible and the amount or range of amounts of any such liability is not reasonably estimable.

Stockholders' Equity	12 Months Ended
Stockholders' Equity	Dec. 31, 2018
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Amended and Restated Certificate of Incorporation Upon the effectiveness of our Amended and Restated Certificate of Incorporation on June 25, 2015, the number of shares of capital stock that is authorized to be issued was increased to 325,000,000 shares, of which 250,000,000 shares are Class A common stock, 50,000,000 shares are Class B common stock and 25,000,000 are undesignated preferred stock. The Class A common stock, Class B common stock and preferred stock have a par value of $0.0001 per share. At December 31, 2018, there were 15,789,000 shares of Class A common stock outstanding, 18,109,000 shares of Class B common stock outstanding and no preferred shares outstanding. Class A Common Stock and Class B Common Stock Except for voting rights, or as otherwise required by applicable law, the shares of our Class A common stock and Class B common stock have the same powers, preferences and rights and rank equally, share ratably and are identical in all respects as to all matters. The rights and preferences are as follows: Dividend Rights. Subject to preferences that may apply to any shares of preferred stock outstanding at the time, the holders of outstanding shares of our Class A common stock and Class B common stock are entitled to receive dividends out of funds legally available at the times and in the amounts that our board of directors may determine. Voting Rights. The holders of our Class A common stock are entitled to one vote per share, and holders of our Class B common stock are entitled to 10 votes per share. The holders of our Class A common stock and Class B common stock will vote together as a single class on all matters submitted to a vote of our stockholders, unless otherwise required by Delaware law or our amended and restated certificate of incorporation. Delaware law could require either holders of our Class A common stock or holders of our Class B common stock to vote separately. In addition, our amended and restated certificate of incorporation requires the approval of the holders of at least a majority of the outstanding shares of our Class B common stock, voting as a separate class to approve a change-in-control transaction. Conversion. Upon the closing of our initial public offering ("IPO"), all shares of our convertible preferred stock and common stock held prior to the offering were converted into shares of Class B common stock. Currently, each share of our Class B common stock is convertible at any time at the option of the holder into one share of our Class A common stock. In addition, each share of our Class B common stock will convert into one share of our Class A common stock upon any transfer, whether or not for value, except for certain transfers described in our amended and restated certificate of incorporation, including, without limitation, (i) a transfer by a partnership or limited liability company that was a registered holder of our Class B common stock at the “effective time,” as defined in our amended and restated certificate of incorporation, to a partner or member thereof at the effective time or (ii) a transfer to a “qualified recipient,” as defined in our amended and restated certificate of incorporation. All the outstanding shares of our Class B common stock will convert automatically into shares of our Class A common stock upon the date when the number of outstanding shares of our Class B common stock represents less than 10% of all outstanding shares of our Class A common stock and Class B common stock. Once converted into our Class A common stock, our Class B common stock may not be reissued. Right to Receive Liquidation Distributions. Upon our dissolution, liquidation or winding-up, the assets legally available for distribution to our stockholders are distributable ratably among the holders of our Class A common stock and Class B common stock, subject to prior satisfaction of all outstanding debt and liabilities and the preferential rights and payment of liquidation preferences, if any, on any outstanding shares of preferred stock. Preferred Stock Effective upon the filing of our amended and restated certificate of incorporation in June 2015, no shares of preferred stock were outstanding because all outstanding shares of our convertible preferred stock converted into our Class B common stock. Pursuant to the terms of our amended and restated certificate of incorporation, our board of directors will be authorized, subject to limitations prescribed by Delaware law, to issue up to 25,000,000 shares of our preferred stock in one or more series, to establish from time to time the number of shares to be included in each series, and to fix the designation, powers, preferences and rights of the shares of each series and any of its qualifications, limitations or restrictions, in each case without further action by our stockholders. The number of authorized shares of any series of preferred stock may be increased or decreased, but not below the number of shares of that series then outstanding, by the affirmative vote of the holders of a majority of the voting power of our outstanding capital stock entitled to vote thereon, or such other vote as may be required by the certificate of designation establishing the series. Treasury Stock In October 2018, our Board of Directors ("Board") authorized a $30.0 million Share Repurchase Program of its outstanding Class A Common Stock. Pursuant to this Program, we repurchased and settled a total of 370,751 shares through open market repurchases, and recorded a $21.6 million reduction to stockholders’ equity at December 31, 2018, which includes broker commissions.

Income Taxes

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Income Taxes

For the years ended December 31, 2018, 2017 and 2016, we recorded income tax expense of $420,000, $58,000, and $67,000, respectively, associated with state taxes and the amortization of tax deductible goodwill that is not an available source of income to realize the deferred tax asset.

On December 22, 2017, the United States government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (the "Tax Act"). The Tax Act has several key provisions impacting accounting for and reporting of income taxes. The most significant provisions applicable to us are the reduction of the U.S. corporate statutory rate from 35% to 21%.

We reviewed and incorporated the impact of the Tax Act in our tax calculations and disclosures. The primary impact on us for the year ended December 31, 2017 stems from the re-measurement of our deferred taxes at the new corporate tax rate of 21%, which reduced our net deferred tax assets, before valuation allowance, by $7.2 million. Due to the full valuation allowance, the change in deferred taxes was fully offset by the change in valuation allowance, except for an immaterial amount that is reflected in income tax expense related to the rate re-measurement of the tax deductible goodwill.

Our effective tax rate differs from the United States federal statutory rate of 21% primarily because our previously reported losses have been offset by a valuation allowance due to uncertainty as to the realization of those losses. Set forth below is a reconciliation of the components that caused our provision for income taxes to differ from amounts computed by applying the United States federal statutory rate of 21% for the year ended December 31, 2018, and 34% for the years ended December 31, 2017 and 2016:



	Year Ended December 31,
	2018		2017		2016
Income tax benefit at the statutory rate	21	%	34	%	34	%
State and local income taxes, net of federal benefit	(3	)	(14	)	7
Stock-based compensation expense	(7	)	(15	)	(4	)
Meals and entertainment	1		2		(2	)
Permanent differences	—		—		(1	)
Change in valuation allowance	(1	)	(60	)	(42	)
Change in federal rate	—		74		—
Research and development tax credits	(9	)	(20	)	7
Provision for income taxes	2	%	1	%	(1	)%

The provision for income tax consists of the following (in thousands):



	Year Ended December 31,
	2018	2017		2016
Current
Federal	—	—		—
State and Local	339	53		24
Current Income Tax Expense	339	53		24
Deferred
Federal	65	(2	)	40
State and Local	16	7		3
Deferred Income tax (benefit) expense	81	5		43
Total income tax provision	420	58		67

The components of deferred tax assets (liabilities) were as follows (in thousands):



	December 31,
	2018			2017
Deferred income tax assets:
Net operating loss carryforwards	$	15,675		$	19,519
Research and development tax credits	11,907			8,278
Intangible assets	143			—
Stock-based compensation	2,203			1,543
Other	2,878			950
Gross deferred tax assets	32,806			30,290
Valuation allowance	(23,002		)	(23,827		)
Deferred tax assets, net of valuation allowance	9,804			6,463
Deferred tax liabilities:
Property, equipment and software	(5,464		)	(4,293		)
Intangible assets	—			(6		)
Capitalized commissions	(1,825		)	—
State taxes	(1,935		)	(1,693		)
Other	(739		)	(549		)
Total deferred tax liabilities	(9,963		)	(6,541		)
Total net deferred tax liabilities	$	(159	)	$	(78	)

At December 31, 2018, we had federal net operating loss carryforwards of $57.7 million, which will begin to expire in 2031. At December 31, 2018, we had state net operating loss carryforwards of $41.2 million, which will begin to expire in 2023. At December 31, 2018, we also had federal and state research and development credit carryforwards of $7.4 million and $7.5 million, respectively. The federal credit carryforwards will begin to expire in 2031, while the majority state credits carryforwards apply indefinitely.

The Internal Revenue Code of 1986, as amended (“IRC”), imposes substantial restrictions on the utilization of NOLs and other tax attributes in the event of an “ownership change” of a corporation. Accordingly, a company’s ability to use pre-change NOLs may be limited as prescribed under IRC Section 382. Events which may cause limitation in the amount of the NOLs and credits that we utilize in any one year include, but are not limited to, a cumulative ownership change of more than 50% over a rolling three-year period. We have undertaken a NOL/382 analysis and have determined that there are no limitations on the NOL carryforwards at December 31, 2018.

Management assesses the available positive and negative evidence to estimate if sufficient future taxable income will be generated to use the existing deferred tax assets in the future. A significant piece of objective negative evidence evaluated was the cumulative loss incurred from inception through December 31, 2018. Such objective evidence limits the ability to consider other subjective positive evidence such as current year taxable income and future income projections. On the basis of this evaluation, at December 31, 2018, a valuation allowance of $23.0 million has been recorded since it is more likely than not that the deferred tax assets will not be realized.

We have recorded a full valuation allowance related to our NOLs, credit carryforwards, and other net deferred tax assets due to the uncertainty of the ultimate realization of the future benefits of those assets. To the extent we determine that all, or a portion of, our valuation allowance is no longer necessary, we will reverse the valuation allowance and recognize an income tax benefit in the reported financial statement earnings in that period. Once the valuation allowance is eliminated or reduced, its reversal will no longer be available to offset our current financial statement tax provision in future periods. We believe that there is a possibility that, within the next six to twelve months, sufficient positive evidence may become available to allow us to reach a conclusion that some or all of the valuation allowance will no longer be needed. Release of the valuation allowance would result in the recognition of certain net deferred tax assets and a decrease to income tax expense for the period the release is recorded. However, the timing and amount of the valuation allowance release are subject to change on the basis of the level of our profitability and other factors.

The change in the valuation allowance for the years ended December 31, 2018, 2017 and 2016 was as follows (in thousands):



	Year Ended December 31,
	2018			2017			2016
Valuation allowance, at beginning of year	$	23,827		$	29,417		$	25,926
Increase (decrease) in valuation allowance	(825		)	(5,590		)	3,491
Valuation allowance, at end of year	$	23,002		$	23,827		$	29,417

The following is a reconciliation of the total amounts of unrecognized tax benefits (in thousands):



	Year Ended December 31,
	2018		2017			2016
Unrecognized tax benefit beginning of year	$	2,105	$	4,032		$	2,867
Decreases-tax positions in prior year	—		(2,210		)	—
Increases-tax positions in current year	872		283			1,165
Unrecognized tax benefit end of year	$	2,977	$	2,105		$	4,032

The unrecognized tax benefits are recorded as a reduction to the deferred tax assets. Since there is a full valuation allowance recorded against the deferred tax assets, the recognition of previously unrecognized tax benefits on uncertain positions would result in no impact to the effective tax rate.

At December 31, 2018 and 2017, we had no accrued interest and penalties related to uncertain income tax positions. We do not anticipate that the amount of unrecognized tax benefits will significantly increase or decrease within the next twelve months.

We are subject to taxation in the United States and various states. Due to the net operating loss carryforwards, our federal and state returns are open to examination by the Internal Revenue Service and state jurisdictions for all years since inception. We are not currently under audit by any taxing authorities.

Stock-Based Compensation

12 Months Ended

Dec. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-Based Compensation

2015 Stock Incentive Plan

In conjunction with our IPO in 2015, our board of directors and stockholders adopted the 2015 Stock Incentive Plan (the "2015 Plan"). Upon adoption of the 2015 Plan, 2,000,000 shares of our Class A common stock were reserved and available for grant and issuance. On January 1 of each subsequent calendar year, the number of shares available for grant and issuance under the 2015 Plan increase by the lesser of (i) the number of shares of our Class A common stock subject to awards granted under the 2015 Plan during the preceding calendar year and (ii) such lesser number of shares of our Class A common stock determined by our board of directors. At December 31, 2018, we have reserved an aggregate of 3,791,744 shares of our Class A common stock for grant and issuance under the 2015 Plan. The number of shares of our Class A common stock is also subject to adjustment in the event of a recapitalization, stock split, reclassification, stock dividend or other change in our capitalization. The 2015 Plan authorizes the award of stock options, stock appreciation rights, RSAs, RSUs, performance awards and stock bonuses. The 2015 Plan provides for the grant of awards to our employees, directors, consultants and independent contractors, subject to certain exceptions. RSUs, PSUs, PSOs, and RSAs have been issued during 2018 pursuant to the 2015 Plan.

Stock options may vest based on the passage of time or the achievement of performance conditions at the discretion of our compensation committee. Our compensation committee may provide for stock options to be exercised only as they vest or to be immediately exercisable with any shares issued on exercise being subject to our right of repurchase that lapses as the shares vest. The maximum term of stock options granted under the 2015 Plan is 10 years. We began granting stock options with performance conditions in 2016.

RSUs and PSUs represent the right on the part of the holder to receive shares of our Class A common stock at a specified date in the future or the achievement of performance conditions at the discretion of our compensation committee, subject to forfeiture of that right due to termination of employment. If an RSU or PSU has not been forfeited, then, on the specified date, we will deliver to the holder of the RSU or PSU shares of our Class A common stock.

2007 Stock Incentive Plan

On February 14, 2007, our board of directors adopted the 2007 Stock Incentive Plan (the “2007 Plan”) as an amendment and restatement to an original 2006 Equity Incentive Plan and was most recently amended in July 2014. Following our IPO, our board of directors determined not to make any further awards under the 2007 Plan. The 2007 Plan expired on February 14, 2017. The 2007 Plan will continue to govern outstanding awards granted under the 2007 Plan. At December 31, 2018, options to purchase an aggregate of 532,978 shares of our Class B common stock remained outstanding under the 2007 Plan. The 2007 Plan is administered by our board of directors. The aggregate number of shares available under the 2007 Plan and the number of shares subject to outstanding options automatically adjusts for any changes in the outstanding common stock by reason of any recapitalization, spin-off, reorganization, reclassification, stock dividend, stock split, reverse stock split, or similar transaction.

Stock Options

A summary of our stock option activity for the year ended December 31, 2018 is as follows (number of shares in thousands):



	Number of Shares		Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Life in Years
Options outstanding at December 31, 2017	1,693		$	10.81	7.3
Options granted	—		—
Options exercised	(170	)	6.09
Options cancelled/forfeited	(10	)	15.09
Options outstanding at December 31, 2018	1,513		$	11.31	6.4

At December 31, 2018:
Options vested and expected to vest	1,513		$	11.32	6.7
Options exercisable⁽¹⁾	1,034		$	8.82	6.4

⁽¹⁾Included in the options exercisable is 31,000 shares which have an early exercise option. The weighted average exercise price of these options is $5.64 per share and the weighted average contractual life in years is 6.1 years.

During the year ended December 31, 2018, no options were granted. Included in the options outstanding at December 31, 2018 are 172,000 and 250,000 PSOs granted in 2017 and 2016, respectively. Vesting of these PSOs is based on the achievement of pre-established performance targets for each of the years ending December 31, 2018 and ending December 31, 2019, and continued employment throughout the performance period. Of the PSOs granted during 2017, 132,000 shares vest based on the achievement of a pre-established free cash flow performance target for the year ending December 31, 2019, assuming achievement of the performance metric at the maximum level, which is 150% of the performance target, resulting in a maximum payout of 100% of the initial target award. The remaining 40,000 PSOs granted during 2017 have a pre-established adjusted gross margin target for the year ending December 31, 2019. PSOs tied to the gross margin performance target have two levels of vesting, with 50% vesting based on the achievement of 110% of the targeted amount and the remaining 50% vesting based on the achievement of 115% of the targeted amount. The 250,000 PSOs granted in 2016 vest based on the achievement of a pre-established free cash flow performance target for the year ending December 31, 2018, assuming achievement of the performance metric at the maximum level, which is 150% of the performance target.

During the year ended December 31, 2018, 250,000 of the PSOs vested based on the achievement of 150% of the pre-established free cash flow performance metric for the year ended December 31, 2017. No expense was recognized as a result of the vesting of PSOs that vested during the twelve months ended December 31, 2018, as all expense was recognized by December 31, 2017.

We recognize expense for the PSOs based on the grant date fair value of the PSOs that we determine are probable of vesting. Adjustments to compensation expense are made each period based on changes in our estimate of the number of PSOs that are probable of vesting. Our stock-based compensation expense for stock options for the years ended December 31, 2018, 2017 and 2016 was $1.6 million, $2.9 million, and $2.4 million, respectively.

The fair value of stock options granted is estimated on the date of grant using the Black-Scholes option-pricing model. No stock options were granted during the year ended December 31, 2018. The following table presents information relating to our stock options granted during the years ended 2017 and 2016:



	Year Ended December 31,
		2017			2016
Stock options granted (in thousands)		172			750
Weighted average exercise price per share		$	24.77		$	12.85
Weighted average grant-date fair value per share		$	9.58		$	4.85
Weighted average Black-Scholes model assumptions:
Risk-free interest rate		2.02		%	1.45		%
Expected term (in years)		6.4			5.9
Expected volatility		35		%	37		%
Expected dividend yield		—			—

At December 31, 2018, the total remaining stock-based compensation expense for unvested stock options was $0.7 million, which is expected to be recognized over a weighted average period of 0.7 years.

The total intrinsic value of options exercised in 2018, 2017 and 2016 was $7.5 million, $4.6 million, and $1.9 million, respectively. This intrinsic value represents the difference between the fair value of our common stock on the date of exercise and the exercise price of each option. Based on the fair value of our common stock at December 31, 2018, the total intrinsic value of all outstanding options was $72.5 million. The total intrinsic value of exercisable options at December 31, 2018 was $52.1 million. The total intrinsic value of options vested and expected to vest at December 31, 2018 was $72.4 million.

The excess tax benefit realized from option exercises during the year ended December 31, 2018, 2017 and 2016 was $7.7 million, $5.2 million and $0.2 million, respectively.

Restricted Stock Units

A summary of activity in connection with our RSUs for the year ended December 31, 2018 is as follows (number of shares in thousands):



	Number of Shares		Weighted Average Grant Date Fair Value per Share
Unvested at December 31, 2017	598		$	19.75
Granted	305		48.12
Vested	(180	)	17.89
Forfeited	(49	)	26.05
Unvested at December 31, 2018	674		$	32.61

During the year ended December 31, 2018, we granted a total of 305,000 RSUs and PSUs: 188,000 RSUs vest annually over four years; 102,000 PSUs vest based upon achievement of a pre-established net revenue growth performance metric for each of the years ended December 31, 2018 and December 31, 2019, 2020 and 2021 and continued employment throughout the performance period; and 15,000 PSUs were granted and vested as a result of the attainment of the 2017 performance metric. The number of PSUs granted, as included in the above table, assumes achievement of the performance metric at 100% of the targeted performance metric. The actual number of shares to be issued at the end of the performance period will range from 0% to 100% of the initial target awards. Achievement of the performance target between 100% and 150% of the performance target will result in a performance-based cash bonus payment between 100% and 165% of the initial target awards.

During the year ended December 31, 2018, 30,000 of the PSUs vested and an additional 15,000 PSUs were granted and vested based on the achievement of 150% of the pre-established free cash flow performance metric for the year ended December 31, 2017. No expense was recognized related to the PSUs that vested during the twelve months ended December 31, 2018, as all expense was recognized by December 31, 2017.

Included in the unvested RSUs and PSUs at December 31, 2018 are 91,000 and 26,000 PSUs granted in 2017 and 2016, respectively. Vesting of these PSUs is based on the achievement of pre-established free cash flow performance targets for each of the years ending December 31, 2018 and ending December 31, 2019, and continued employment throughout the performance period. The number of PSUs granted assumes achievement of the performance metric at 100% of the performance target. For the PSUs granted in 2017, the actual number of shares to be issued at the end of the performance period will range from 0% to 165% of the initial target award. For the PSUs granted in 2016, the actual number of shares to be issued at the end of the performance period will range from 0% to 150% of the initial target award.

We recognize expense for the PSUs based on the grant date fair value of the PSUs that we determine are probable of vesting. Adjustments to compensation expense are made each period based on changes in our estimate of the number of PSUs that are probable of vesting. Our stock-based compensation expense for the RSUs and PSUs for the years ended December 31, 2018, 2017 and 2016, was $5.5 million, $3.6 million and $1.8 million, respectively.

At December 31, 2018, the total remaining stock-based compensation expense for these RSUs was $15.0 million, which is expected to be recognized over a weighted average period of 2.2 years.

Restricted Stock Awards

A summary of activity in connection with our RSAs for the year ended December 31, 2018 is as follows (number of shares in thousands):



	Number of Shares		Weighted- Average Grant Date Fair Value per Share
Unvested at December 31, 2017	16		$	20.93
Granted	5		61.05
Vested	(15	)	21.97
Forfeited	—		—
Unvested at December 31, 2018	6		$	51.36

We have the right to repurchase any unvested RSAs. RSAs vest over a four-year period for employees and over a one-year period for non-employee directors. For the years ended December 31, 2018, 2017 and 2016, we recognized stock-based compensation expense for RSAs of $335,000, $358,000 and $454,000, respectively. During 2018, the grant date fair value of the shares vested was $335,000.

At December 31, 2018, the total remaining stock-based compensation expense for unvested RSAs was $0.1 million, which is expected to be recognized over a weighted average period of 0.5 years.

Revenue and Other Information

12 Months Ended

Dec. 31, 2018

Segment Reporting [Abstract]

Revenue and Other Information

The following table presents our revenue categories for the years ended December 31, 2018, 2017 and 2016 (in thousands):



	Year Ended December 31,
	2018		2017		2016
Core solutions	$	70,549	$	57,132	$	43,775
Value+ services	113,072		80,847		56,965
Other	6,450		5,824		4,846
Total revenue	$	190,071	$	143,803	$	105,586

Our revenue is generated primarily from United States customers. All of our property and equipment is located in the United States.

Retirement Plans	12 Months Ended
Retirement Plans	Dec. 31, 2018
Retirement Benefits [Abstract]
Retirement Plans	Retirement Plans We have a 401(k) retirement and savings plan made available to all employees. The 401(k) plan allows each participant to contribute up to an amount not to exceed an annual statutory maximum. We may, at our discretion, make matching contributions to the 401(k) plan. Cash contributions to the plan were $1.6 million, $0.8 million and $1.1 million, for the years ended December 31, 2018, 2017 and 2016, respectively.

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Acquisition of Dynasty On January 7, 2019, we entered into an Agreement and Plan of Merger with Riviera Mar, Inc., our wholly-owned subsidiary ("Merger Subsidiary"), Dynasty Marketplace, Inc. ("Dynasty") and Fortis Advisor's LLC, in its capacity as agent for the stockholders of Dynasty (collectively, the "Dynasty Stockholders"), pursuant to which, Merger Subsidiary was merged with and into Dynasty, resulting in Dynasty becoming our wholly-owned subsidiary (the "Transaction"). Dynasty is in the business of developing artificial intelligence-based software solutions for real estate businesses. The consideration paid to the Dynasty Stockholders was $60.2 million, less certain adjustments set forth in the Merger Agreement, of which $6.0 million will be retained by us to satisfy any indemnification claims. We are currently in the process of valuing the assets acquired and liabilities assumed pursuant to the Transaction. We will allocate the purchase price to tangible and identifiable intangible assets acquired and liabilities assumed based on their estimated fair values. Given the recent closing of the Transaction, the assessment of the acquisition-date fair values of the assets acquired and the liabilities assumed and the determination of the estimated useful lives of long-lived assets and finite-lived intangibles are pending the completion of appraisals; therefore we are unable to disclose the purchase price allocation or pro forma results of operations for the year ended December 31, 2018. We expect to allocate the majority of the consideration between technology and goodwill. Stock Repurchase Program On February 20, 2019 the Board of Directors authorized a $100.0 million Share Repurchase Program of its outstanding Class A Common Stock. Under the Program, share repurchases may be made from time to time as directed by a Committee consisting of three Directors, in open market purchases or privately negotiated transactions at a repurchase price that the members of the Committee unanimously believe is below intrinsic value conservatively determined. The Program does not obligate the Company to repurchase any specific dollar amount or number of shares, there is no expiration date to the Program, and it may be modified, suspended or terminated at any time and for any reason. The Company has not initiated any repurchases under this Program as of February 28, 2019. Pursuant to the $30.0 million Share Repurchase Program announced in October 2018, the Company has repurchased 370,751 shares for an aggregate purchase price of $21.6 million. The balance of $8.4 million remaining under the October authorization is included within the $100.0 million Share Repurchase Program authorized on February 20, 2019.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Basis of Presentation and Significant Accounting Policies

The accompanying Consolidated Financial Statements were prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”).

The Company analyzes the expenses recognized in the statement of operations using the classification method based on the functional category to which the expense belongs.

Principles of Consolidation

Use of Estimates

Segment Information

Concentrations of Credit Risk

Concentrations of credit risk with respect to accounts receivable and revenue are limited due to a large, diverse customer base.

Fair Value Measurements

Level 1 - Quoted prices in active markets for identical assets or liabilities or funds.

Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

Cash and Cash Equivalents

Cash and Cash Equivalents and Restricted Cash

Restricted Cash

Investment Securities

Accounts Receivable

Property and Equipment



Asset Type		Depreciation Period
Data center and computer equipment		3 years
Furniture and fixtures		7 years
Office equipment		2 to 5 years
Leasehold improvements		Shorter of remaining life of lease or asset life

Leases

Leases are evaluated and classified as either operating or capital leases. All of our office space leases are operating leases.

The deferred rent liability was amortized as a reduction of rent expense over the lives of the leases.

Capitalized Software Development Costs

Goodwill and Intangible Assets

No impairment losses were recorded for goodwill during the years ended December 31, 2018, 2017 and 2016.

Impairment of Long-Lived Assets

Business Combinations

Acquisition-related transaction costs are not included as a component of consideration transferred, but are accounted for as an operating expense in the period in which the costs are incurred.

Revenue Recognition

Cost of Revenue

Deferred Costs

Revenue Recognition

Core Solutions

Value+ Services

Other Revenues

Contracts with Multiple Performance Obligations

Deferred Revenues

Practical Expedients

We do not disclose the value of unsatisfied performance obligations for contracts with an original expected term of one year or less.

Sales and Marketing, General and Administrative

General and Administrative

Sales and Marketing

Research and Product Development

Depreciation and Amortization

Stock-Based Compensation

Stock Options

For the year ended December 31, 2018, we did not grant time-based stock option or PSOs.

Restricted Stock Units

Performance-Based Equity Awards

Forfeiture Rate

Income Taxes

Net Income (Loss) per Share

Recently Accounting Pronouncements

Recently Adopted Accounting Pronouncements

The cumulative effects of the changes made to our Consolidated Balance Sheet at January 1, 2018 for the adoption of the New Revenue Standard were as follows (in thousands):



	Balance at December 31, 2017			Adjustments		Balance at January 1, 2018
Assets
Prepaid expenses and other current assets	$	4,546		$	1,148	$	5,694
Other assets	1,238			1,816		3,054

Equity
Accumulated deficit	$	(67,247	)	$	2,964	$	(64,283	)

The following tables presents the current period impacts of adopting the New Revenue Standard on our Consolidated Financial Statements (in thousands):

Consolidated Balance Sheet:



	December 31, 2018
	As Reported			Balances Without Adoption of ASU 2014-09			Effect of Adoption
Assets
Prepaid expenses and other current assets	$	11,775		$	8,548		$	3,227
Other assets	7,688			3,709			3,979

Equity
Accumulated deficit	$	(44,316	)	$	(51,522	)	$	7,206

Consolidated Statements of Operations:



	Year Ended December 31, 2018
	As Reported		Balances Without Adoption of ASU 2014-09		Effect of Adoption
Costs and operating expenses:
Cost of revenue (exclusive of depreciation and amortization)	$	73,549	$	73,786	$	(237	)
Sales and marketing	33,288		37,295		(4,007		)
Total costs and operating expenses	170,415		174,659		(4,244		)
Income from operations	19,656		15,412		4,244
Income before provision for income taxes	20,387		16,143		4,244
Net income	$	19,967	$	15,723	$	4,244

Net income per common share:
Basic	$	0.59	$	0.46	$	0.13
Diluted	$	0.56	$	0.44	$	0.12

Recent Accounting Pronouncements Not Yet Adopted

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Schedule of Estimated Useful Lives of Property and Equipment

The estimated useful lives of our property and equipment are as follows:



Asset Type		Depreciation Period
Data center and computer equipment		3 years
Furniture and fixtures		7 years
Office equipment		2 to 5 years
Leasehold improvements		Shorter of remaining life of lease or asset life

Property and equipment consists of the following at December 31, 2018 and 2017 (in thousands):



	December 31,
	2018			2017
Data center and computer equipment	$	6,854		$	5,233
Furniture and fixtures	2,928			2,415
Office equipment	798			763
Leasehold improvements	5,254			5,029
Construction in process	79			—
Gross property and equipment	15,913			13,440
Less: Accumulated depreciation	(9,042		)	(6,744		)
Total property and equipment, net	$	6,871		$	6,696

Schedule of Weighted Average Number of Shares

The following table presents a reconciliation of our weighted average number of Class A and Class B common shares used to compute net income (loss) per share (in thousands):



	Year Ended December 31,
	2018	2017	2016
Weighted average common shares outstanding	34,139	33,876	33,639
Less: Weighted average unvested restricted shares subject to repurchase	11	27	78
Weighted average common shares outstanding; basic	34,128	33,849	33,561

Weighted average common shares outstanding; basic	34,128	33,849	33,561
Plus: Weighted average options, restricted stock units and restricted shares used to compute diluted net income per common share	1,434	1,302	—
Weighted average common shares outstanding; diluted	35,562	35,151	33,561

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The following table presents the number of anti-dilutive common shares excluded from the calculation of weighted average number of shares used to compute diluted net income (loss) per share for the years ended December 31, 2018, 2017 and 2016 (in thousands):



	December 31,
	2018	2017	2016
Options to purchase common stock	—	—	1,718
Unvested RSAs	—	—	46
Unvested restricted stock units	10	21	496
Contingent restricted stock units⁽¹⁾	—	6	34
Total shares excluded from diluted net income per common share	10	27	2,294

Schedule of New Accounting Pronouncements and Changes in Accounting Principles

he cumulative effects of the changes made to our Consolidated Balance Sheet at January 1, 2018 for the adoption of the New Revenue Standard were as follows (in thousands):



	Balance at December 31, 2017			Adjustments		Balance at January 1, 2018
Assets
Prepaid expenses and other current assets	$	4,546		$	1,148	$	5,694
Other assets	1,238			1,816		3,054

Equity
Accumulated deficit	$	(67,247	)	$	2,964	$	(64,283	)

The following tables presents the current period impacts of adopting the New Revenue Standard on our Consolidated Financial Statements (in thousands):

Consolidated Balance Sheet:



	December 31, 2018
	As Reported			Balances Without Adoption of ASU 2014-09			Effect of Adoption
Assets
Prepaid expenses and other current assets	$	11,775		$	8,548		$	3,227
Other assets	7,688			3,709			3,979

Equity
Accumulated deficit	$	(44,316	)	$	(51,522	)	$	7,206

Consolidated Statements of Operations:



	Year Ended December 31, 2018
	As Reported		Balances Without Adoption of ASU 2014-09		Effect of Adoption
Costs and operating expenses:
Cost of revenue (exclusive of depreciation and amortization)	$	73,549	$	73,786	$	(237	)
Sales and marketing	33,288		37,295		(4,007		)
Total costs and operating expenses	170,415		174,659		(4,244		)
Income from operations	19,656		15,412		4,244
Income before provision for income taxes	20,387		16,143		4,244
Net income	$	19,967	$	15,723	$	4,244

Net income per common share:
Basic	$	0.59	$	0.46	$	0.13
Diluted	$	0.56	$	0.44	$	0.12

Acquisition of WegoWise (Tables)

12 Months Ended

Dec. 31, 2018

Business Combinations [Abstract]

Schedule of Purchase Price Allocation

The following table presents the purchase price allocation (in thousands) as well as the useful lives of the acquired intangible assets over which they are amortized on a straight-line basis, as this approximates the pattern in which economic benefits of the assets are consumed:



	Amount (in thousands)		Estimated Useful Life (in years)
Net tangible assets	$	270
Identified intangible assets:
Customer relationships	1,170		5.0
Database	3,620		10.0
Trademark and trade name	370		10.0
Non-compete agreement	60		5.0
Backlog	140		1.0
Total intangible assets subject to amortization	5,360		8.6
Goodwill	8,811		Indefinite
Purchase consideration, paid in cash	$	14,441

Schedule of Pro Forma Information

The unaudited pro forma results are as follows (in thousands, except per share amounts):



	Year Ended December 31,
	2018		2017
Revenue	$	192,523	$	146,859
Net income	$	18,247	$	5,052

Net income per common share:
Basic	$	0.53	$	0.15
Diluted	$	0.51	$	0.14

Investment Securities and Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Schedule of Available-for-sale Securities

Investment securities classified as available-for-sale consisted of the following at December 31, 2018 and 2017 (in thousands):



	December 31, 2018
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Corporate bonds	$	23,720	$	—	$	(163	)	$	23,557
Agency securities	4,345		4		(19		)	4,330
Total available-for-sale investment securities	$	28,065	$	4	$	(182	)	$	27,887



	December 31, 2017
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Corporate bonds	$	38,383	$	—	$	(166	)	$	38,217
Agency securities	11,045		—		(42		)	11,003
Certificates of deposit	2,982		1		(2		)	2,981
Total available-for-sale investment securities	$	52,410	$	1	$	(210	)	$	52,201

Available-for-sale Investments, by Remaining Contract Maturity



	December 31, 2018				December 31, 2017
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Due in one year or less	$	16,738	$	16,631	$	29,850	$	29,800
Due after one year through three years	11,327		11,256		22,560		22,401
Total available-for-sale investment securities	$	28,065	$	27,887	$	52,410	$	52,201

Schedule of Sales and Maturities

During the years ended December 31, 2018 and 2017, we had sales and maturities (which include calls) of investment securities, as follows (in thousands):



	Year Ended December 31, 2018
	Gross Realized Gains		Gross Realized Losses			Gross Proceeds from Sales			Gross Proceeds from Maturities
Corporate bonds	$	—	$	(11	)	$	(6,624	)	$	(19,307	)
Agency securities	4		(14		)	(5,671		)	(7,000		)
Certificates of deposit	—		—			—			(2,982		)
Treasury securities	—		(10		)	(8,605		)	(3,530		)
	$	4	$	(35	)	$	(20,900	)	$	(32,819	)



	Year Ended December 31, 2017
	Gross Realized Gains		Gross Realized Losses		Gross Proceeds from Sales		Gross Proceeds from Maturities
Agency securities	$	1	$	—	$	15	$	3,294
Corporate bonds	—		—		—		10,690
Certificates of deposit	—		—		—		2,490
	$	1	$	—	$	15	$	16,474

Fair Value, Assets Measured on Recurring Basis

The following tables presents our financial assets and liabilities measured at fair value on a recurring basis at December 31, 2018 and 2017, by level within the fair value hierarchy (in thousands):



	December 31, 2018
	Level 1		Level 2		Level 3		Total Fair Value
Cash equivalents:
Money market funds	$	10,694	$	—	$	—	$	10,694
Available-for-sale investment securities:
Corporate bonds	—		23,557		—		23,557
Agency securities	—		4,330		—		4,330
Total	$	10,694	$	27,887	$	—	$	38,581



	December 31, 2017
	Level 1		Level 2		Level 3		Total Fair Value
Cash equivalents:
Money market funds	$	5,524	$	—	$	—	$	5,524
Available-for-sale investment securities:
Corporate bonds	—		38,217		—		38,217
Agency securities	—		11,003		—		11,003
Certificates of deposit	2,981		—		—		2,981
Total Assets	$	8,505	$	49,220	$	—	$	57,725

Fair Value, Liabilities Measured on Recurring Basis

The following tables presents our financial assets and liabilities measured at fair value on a recurring basis at December 31, 2018 and 2017, by level within the fair value hierarchy (in thousands):



	December 31, 2018
	Level 1		Level 2		Level 3		Total Fair Value
Cash equivalents:
Money market funds	$	10,694	$	—	$	—	$	10,694
Available-for-sale investment securities:
Corporate bonds	—		23,557		—		23,557
Agency securities	—		4,330		—		4,330
Total	$	10,694	$	27,887	$	—	$	38,581



	December 31, 2017
	Level 1		Level 2		Level 3		Total Fair Value
Cash equivalents:
Money market funds	$	5,524	$	—	$	—	$	5,524
Available-for-sale investment securities:
Corporate bonds	—		38,217		—		38,217
Agency securities	—		11,003		—		11,003
Certificates of deposit	2,981		—		—		2,981
Total Assets	$	8,505	$	49,220	$	—	$	57,725

Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

Property and Equipment

The estimated useful lives of our property and equipment are as follows:



Asset Type		Depreciation Period
Data center and computer equipment		3 years
Furniture and fixtures		7 years
Office equipment		2 to 5 years
Leasehold improvements		Shorter of remaining life of lease or asset life

Property and equipment consists of the following at December 31, 2018 and 2017 (in thousands):



	December 31,
	2018			2017
Data center and computer equipment	$	6,854		$	5,233
Furniture and fixtures	2,928			2,415
Office equipment	798			763
Leasehold improvements	5,254			5,029
Construction in process	79			—
Gross property and equipment	15,913			13,440
Less: Accumulated depreciation	(9,042		)	(6,744		)
Total property and equipment, net	$	6,871		$	6,696

Internal-Use Software Development Costs (Tables)

12 Months Ended

Dec. 31, 2018

Research and Development [Abstract]

Schedule of Capitalized Computer Software

Internal-use software development costs were as follows (in thousands):



	December 31,
	2018			2017
Internal use software development costs, gross	$	58,237		$	44,626
Less: Accumulated amortization	(37,752		)	(27,017		)
Internal use software development costs, net	$	20,485		$	17,609

Scheduled of Future Amortization Expense

Future amortization expense with respect to capitalized software development costs at December 31, 2018 is estimated as follows (in thousands):



Years Ending December 31,
2019	$	10,664
2020	6,848
2021	2,950
2022	23
Total amortization expense	$	20,485

Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill

The change in the carrying amount of goodwill is as follows (in thousands):



Goodwill at December 31, 2017	$	6,737
Goodwill from acquisition of WegoWise	8,811
Goodwill at December 31, 2018	$	15,548

Schedule of Finite-Lived Intangible Assets

Intangible assets consisted of the following at December 31, 2018 and 2017 (in thousands, except years):



	December 31, 2018
	Gross Carrying Value		Accumulated Amortization			Net Carrying Value		Weighted Average Useful Life in Years
Customer relationships	$	1,960	$	(728	)	$	1,232	5.0
Database	3,620		(121		)	3,499		10.0
Technology	4,811		(4,506		)	305		8.0
Trademarks and trade names	1,300		(642		)	658		9.0
Partner relationships	680		(680		)	—		3.0
Non-compete agreements	100		(44		)	56		4.0
Domain names	273		(273		)	—		5.0
Patents	285		(233		)	52		5.0
Backlog	140		(47		)	93		1.0
	$	13,169	$	(7,274	)	$	5,895	7.0



	December 31, 2017
	Gross Carrying Value		Accumulated Amortization			Net Carrying Value		Weighted Average Useful Life in Years
Customer relationships	$	790	$	(538	)	$	252	5.0
Technology	4,811		(3,871		)	940		6.0
Trademarks	930		(539		)	391		9.0
Partner relationships	680		(623		)	57		3.0
Non-compete agreements	40		(37		)	3		3.0
Domain names	273		(273		)	—		5.0
Patents	285		(203		)	82		5.0
	$	7,809	$	(6,084	)	$	1,725	5.9

Schedule of Finite-Lived Intangible Assets Amortization Expense

Amortization expense for each of the five fiscal years through December 31, 2023 is estimated as follows (in thousands):



Years Ending December 31,
2019	$	1,091
2020	904
2021	769
2022	706
2023	563
Thereafter	1,862
Total amortization expense	$	5,895

Long-term Debt (Tables)

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Summary of Long-term Debt

The following is a summary of our long-term debt at December 31, 2018 (in thousands):



Principal amounts due under term loan	$	50,000
Less: Debt financing costs	(185		)
Long-term debt, net of unamortized debt financing costs	49,815
Less: Current portion of long-term debt	(1,213		)
Total long-term debt, net of current portion	48,602

Schedule of Principal payments for Term Loan

Scheduled principal payments for the Term Loan at December 31, 2018 are as follows (in thousands):



Years Ending December 31,
2019		1,250
2020		1,250
2021		2,500
2022		2,500
2023		42,500
Total principal payments		50,000

Summary of Total Deferred Debt Financing Costs

The following table presents the total deferred debt financing costs for the term loan and the Revolving Facility (in thousands):



	Term Loan		Revolving Facility
Deferred financing costs at December 31, 2017	$	—	$	175
Deferred financing costs Second Amendment	185		185
Amortization of deferred financing costs	—		(60		)
Deferred financing costs at December 31, 2018	$	185	$	300

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 835
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-Section 45
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-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 505
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-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21506-112644

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21538-112644

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
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-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ Details

Commitment and Contingencies (Tables)

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Schedule of Future Minimum Payments for Operating Leases

A summary of our future minimum payments for obligations under non-cancellable operating leases is as follows (in thousands):



Years Ending December 31,
2019	$	4,211
2020	4,889
2021	4,038
2022	2,717
2023	2,053
Thereafter	9,128
Total lease commitments	$	27,036

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation

Set forth below is a reconciliation of the components that caused our provision for income taxes to differ from amounts computed by applying the United States federal statutory rate of 21% for the year ended December 31, 2018, and 34% for the years ended December 31, 2017 and 2016:



	Year Ended December 31,
	2018		2017		2016
Income tax benefit at the statutory rate	21	%	34	%	34	%
State and local income taxes, net of federal benefit	(3	)	(14	)	7
Stock-based compensation expense	(7	)	(15	)	(4	)
Meals and entertainment	1		2		(2	)
Permanent differences	—		—		(1	)
Change in valuation allowance	(1	)	(60	)	(42	)
Change in federal rate	—		74		—
Research and development tax credits	(9	)	(20	)	7
Provision for income taxes	2	%	1	%	(1	)%

Schedule of Components of Income Tax Expense (Benefit)

The provision for income tax consists of the following (in thousands):



	Year Ended December 31,
	2018	2017		2016
Current
Federal	—	—		—
State and Local	339	53		24
Current Income Tax Expense	339	53		24
Deferred
Federal	65	(2	)	40
State and Local	16	7		3
Deferred Income tax (benefit) expense	81	5		43
Total income tax provision	420	58		67

Schedule of Deferred Tax Assets and Liabilities

The components of deferred tax assets (liabilities) were as follows (in thousands):



	December 31,
	2018			2017
Deferred income tax assets:
Net operating loss carryforwards	$	15,675		$	19,519
Research and development tax credits	11,907			8,278
Intangible assets	143			—
Stock-based compensation	2,203			1,543
Other	2,878			950
Gross deferred tax assets	32,806			30,290
Valuation allowance	(23,002		)	(23,827		)
Deferred tax assets, net of valuation allowance	9,804			6,463
Deferred tax liabilities:
Property, equipment and software	(5,464		)	(4,293		)
Intangible assets	—			(6		)
Capitalized commissions	(1,825		)	—
State taxes	(1,935		)	(1,693		)
Other	(739		)	(549		)
Total deferred tax liabilities	(9,963		)	(6,541		)
Total net deferred tax liabilities	$	(159	)	$	(78	)

Summary of Valuation Allowance

The change in the valuation allowance for the years ended December 31, 2018, 2017 and 2016 was as follows (in thousands):



	Year Ended December 31,
	2018			2017			2016
Valuation allowance, at beginning of year	$	23,827		$	29,417		$	25,926
Increase (decrease) in valuation allowance	(825		)	(5,590		)	3,491
Valuation allowance, at end of year	$	23,002		$	23,827		$	29,417

Schedule of Unrecognized Tax Benefits Roll Forward

The following is a reconciliation of the total amounts of unrecognized tax benefits (in thousands):



	Year Ended December 31,
	2018		2017			2016
Unrecognized tax benefit beginning of year	$	2,105	$	4,032		$	2,867
Decreases-tax positions in prior year	—		(2,210		)	—
Increases-tax positions in current year	872		283			1,165
Unrecognized tax benefit end of year	$	2,977	$	2,105		$	4,032

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of Stock Option Activity

A summary of our stock option activity for the year ended December 31, 2018 is as follows (number of shares in thousands):



	Number of Shares		Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Life in Years
Options outstanding at December 31, 2017	1,693		$	10.81	7.3
Options granted	—		—
Options exercised	(170	)	6.09
Options cancelled/forfeited	(10	)	15.09
Options outstanding at December 31, 2018	1,513		$	11.31	6.4

At December 31, 2018:
Options vested and expected to vest	1,513		$	11.32	6.7
Options exercisable⁽¹⁾	1,034		$	8.82	6.4

Schedule of Valuation Assumptions, Stock Options

The following table presents information relating to our stock options granted during the years ended 2017 and 2016:



	Year Ended December 31,
		2017			2016
Stock options granted (in thousands)		172			750
Weighted average exercise price per share		$	24.77		$	12.85
Weighted average grant-date fair value per share		$	9.58		$	4.85
Weighted average Black-Scholes model assumptions:
Risk-free interest rate		2.02		%	1.45		%
Expected term (in years)		6.4			5.9
Expected volatility		35		%	37		%
Expected dividend yield		—			—

Schedule of Restricted Stock Units Activity

A summary of activity in connection with our RSUs for the year ended December 31, 2018 is as follows (number of shares in thousands):



	Number of Shares		Weighted Average Grant Date Fair Value per Share
Unvested at December 31, 2017	598		$	19.75
Granted	305		48.12
Vested	(180	)	17.89
Forfeited	(49	)	26.05
Unvested at December 31, 2018	674		$	32.61

Schedule of Restricted Stock Activity

A summary of activity in connection with our RSAs for the year ended December 31, 2018 is as follows (number of shares in thousands):



	Number of Shares		Weighted- Average Grant Date Fair Value per Share
Unvested at December 31, 2017	16		$	20.93
Granted	5		61.05
Vested	(15	)	21.97
Forfeited	—		—
Unvested at December 31, 2018	6		$	51.36

Revenue and Other Information (Tables)

12 Months Ended

Dec. 31, 2018

Segment Reporting [Abstract]

Schedule of Product Information by Revenue Categories

The following table presents our revenue categories for the years ended December 31, 2018, 2017 and 2016 (in thousands):



	Year Ended December 31,
	2018		2017		2016
Core solutions	$	70,549	$	57,132	$	43,775
Value+ services	113,072		80,847		56,965
Other	6,450		5,824		4,846
Total revenue	$	190,071	$	143,803	$	105,586

Summary of Significant Accounting Policies - Additional Information (Details)	1 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2018 USD ($) reporting_unit operating_segment	Dec. 31, 2017 USD ($) operating_segment	Dec. 31, 2016 USD ($)
Accounting Policies [Abstract]
Number of operating segments \| operating_segment		1
Number of reportable segments \| operating_segment			1
Restricted cash included in other assets		$ 430,000	$ 427,000	$ 427,000
Finite-Lived Intangible Assets [Line Items]
Deferred rent liability		6,900,000	1,100,000
Impairment charges related to the identified long-lived assets		0	0	0
Goodwill		15,548,000	6,737,000
Deferred revenue recognized during the period		7,100,000
Deferred costs		7,200,000
Deferred costs, current		3,200,000
Deferred costs, noncurrent		4,000,000
Amortization expense		2,000,000
Advertising expense		4,500,000	$ 3,600,000	$ 3,600,000
Options to purchase common stock
Finite-Lived Intangible Assets [Line Items]
Dividend yield		$ 0.00
Unvested restricted stock units
Finite-Lived Intangible Assets [Line Items]
Vesting period	4 years	4 years
Capitalized Software Development Costs
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives (in years)		3 years
Goodwill
Finite-Lived Intangible Assets [Line Items]
Number of reporting units \| reporting_unit		1

Summary of Significant Accounting Policies - Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2017
Data center and computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	3 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	7 years
Office equipment \| Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	2 years
Office equipment \| Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	5 years

Summary of Significant Accounting Policies - Net Income (Loss) per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average common shares outstanding	34,139	33,876	33,639
Less: Weighted average unvested restricted shares subject to repurchase	11	27	78
Weighted average common shares outstanding; basic	34,128	33,849	33,561
Plus: Weighted average options, restricted stock units and restricted shares used to compute diluted net income per common share	1,434	1,302	0
Weighted average common shares outstanding; diluted	35,562	35,151	33,561
Shares excluded from net loss per share attributable to common stockholders	10	27	2,294
Performance Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from net loss per share attributable to common stockholders	358	548
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from net loss per share attributable to common stockholders	0	0	1,718
Unvested RSAs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from net loss per share attributable to common stockholders	0	0	46
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from net loss per share attributable to common stockholders	10	21	496
Contingent restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from net loss per share attributable to common stockholders	0	6	34

Summary of Significant Accounting Policies - Recent Accounting Pronouncements Not Yet Adopted (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jul. 27, 2018	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Prepaid expenses and other current assets	$ 11,775	$ 4,546			$ 5,694
Other assets	7,688	1,238			3,054
Accumulated deficit	(44,316)	(67,247)			(64,283)
Costs and operating expenses:
Cost of revenue (exclusive of depreciation and amortization)	73,549	55,283	$ 44,630
Sales and marketing	33,288	28,709	28,827
Total costs and operating expenses	170,415	134,468	114,009
Income from operations	19,656	9,335	(8,423)
Income before provision for income taxes	20,387	9,774	(8,214)
Net income (loss)	$ 19,967	$ 9,716	$ (8,281)
Net income (loss) per common share:
Basic (in usd per share)	$ 0.59	$ 0.29	$ (0.25)
Diluted (in usd per share)	$ 0.56	$ 0.28	$ (0.25)
Minimum payments under operating leases	$ 27,036			$ 16,600
Balances Without Adoption of ASU 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Prepaid expenses and other current assets	8,548	$ 4,546
Other assets	3,709	1,238
Accumulated deficit	(51,522)	$ (67,247)
Costs and operating expenses:
Cost of revenue (exclusive of depreciation and amortization)	73,786
Sales and marketing	37,295
Total costs and operating expenses	174,659
Income from operations	15,412
Income before provision for income taxes	16,143
Net income (loss)	$ 15,723
Net income (loss) per common share:
Basic (in usd per share)	$ 0.46
Diluted (in usd per share)	$ 0.44
ASU 2014-09 \| Effect of Adoption
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Prepaid expenses and other current assets	$ 3,227				1,148
Other assets	3,979				1,816
Accumulated deficit	7,206				$ 2,964
Costs and operating expenses:
Cost of revenue (exclusive of depreciation and amortization)	(237)
Sales and marketing	(4,007)
Total costs and operating expenses	(4,244)
Income from operations	4,244
Income before provision for income taxes	4,244
Net income (loss)	$ 4,244
Net income (loss) per common share:
Basic (in usd per share)	$ 0.13
Diluted (in usd per share)	$ 0.12

Acquisition of WegoWise (Details) - USD ($) $ in Thousands		4 Months Ended
Acquisition of WegoWise (Details) - USD ($) $ in Thousands	Aug. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill		$ 15,548	$ 6,737
WegoWise, Inc.
Business Acquisition [Line Items]
Consideration total, gross	$ 14,400
Escrow consideration	2,000
Net tangible assets	270
Identified intangible assets	5,360
Goodwill	8,811
Purchase consideration, paid in cash	$ 14,441
Intangible assets, estimated useful life	8 years 7 months 10 days
Acquisition Costs		240
Revenue from acquiree		400
Net income (loss) from acquiree		$ (1,400)
WegoWise, Inc. \| Customer relationships
Business Acquisition [Line Items]
Identified intangible assets	$ 1,170
Intangible assets, estimated useful life	5 years
WegoWise, Inc. \| Database
Business Acquisition [Line Items]
Identified intangible assets	$ 3,620
Intangible assets, estimated useful life	10 years
WegoWise, Inc. \| Trademark and trade name
Business Acquisition [Line Items]
Identified intangible assets	$ 370
Intangible assets, estimated useful life	10 years
WegoWise, Inc. \| Non-compete agreements
Business Acquisition [Line Items]
Identified intangible assets	$ 60
Intangible assets, estimated useful life	5 years
WegoWise, Inc. \| Backlog
Business Acquisition [Line Items]
Identified intangible assets	$ 140
Intangible assets, estimated useful life	1 year

Acquisition of WegoWise - Pro Forma Information (Details) - WegoWise, Inc. - USD ($) $ / shares in Units, $ in Thousands	4 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Revenue from acquiree	$ 400
Net income (loss) from acquiree	$ (1,400)
Revenue		$ 192,523	$ 146,859
Net income		$ 18,247	$ 5,052
Net income per common share:
Basic (in dollars per share)		$ 0.53	$ 0.15
Diluted (in dollars per share)		$ 0.51	$ 0.14

Investment Securities and Fair Value Measurements - Investment Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 28,065	$ 52,410
Gross Unrealized Gains	4	1
Gross Unrealized Losses	(182)	(210)
Estimated Fair Value	$ 27,887	$ 52,201
Investment contractual maturities	36 months	36 months
Amortized Cost, due in one year or less	$ 16,738	$ 29,850
Estimated Fair Value, due in one year or less	16,631	29,800
Amortized Cost, due after one year through three years	11,327	22,560
Estimated Fair Value, due after one year through three years	11,256	22,401
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	23,720	38,383
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(163)	(166)
Estimated Fair Value	23,557	38,217
Agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,345	11,045
Gross Unrealized Gains	4	0
Gross Unrealized Losses	(19)	(42)
Estimated Fair Value	$ 4,330	11,003
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		2,982
Gross Unrealized Gains		1
Gross Unrealized Losses		(2)
Estimated Fair Value		$ 2,981

Investment Securities and Fair Value Measurements - Sales and Maturities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Securities, Available-for-sale [Line Items]
Gross Realized Gains	$ 4	$ 1
Gross Realized Losses	(35)	0
Gross Proceeds from Sales	20,900	15	$ 12,559
Gross Proceeds from Maturities	32,819	16,474	21,337
Amortization and accretion of premium and discount	1,000	700	$ 500
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Gross Realized Gains	0	0
Gross Realized Losses	(11)	0
Gross Proceeds from Sales	6,624	0
Gross Proceeds from Maturities	19,307	10,690
Agency securities
Debt Securities, Available-for-sale [Line Items]
Gross Realized Gains	4	1
Gross Realized Losses	(14)	0
Gross Proceeds from Sales	5,671	15
Gross Proceeds from Maturities	7,000	3,294
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Gross Realized Gains	0	0
Gross Realized Losses	0	0
Gross Proceeds from Sales	0	0
Gross Proceeds from Maturities	2,982	$ 2,490
Treasury securities
Debt Securities, Available-for-sale [Line Items]
Gross Realized Gains	0
Gross Realized Losses	(10)
Gross Proceeds from Sales	8,605
Gross Proceeds from Maturities	$ 3,530

Investment Securities and Fair Value Measurements - Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale investment securities:	$ 27,887	$ 52,201
Corporate bonds
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale investment securities:	23,557	38,217
Agency securities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale investment securities:	4,330	11,003
Certificates of deposit
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale investment securities:		2,981
Fair value, measurements, recurring
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total Assets	38,581	57,725
Fair value, measurements, recurring \| Corporate bonds
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale investment securities:	23,557	38,217
Fair value, measurements, recurring \| Agency securities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale investment securities:	4,330	11,003
Fair value, measurements, recurring \| Certificates of deposit
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale investment securities:		2,981
Fair value, measurements, recurring \| Money market funds
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Cash equivalents:	10,694	5,524
Fair value, measurements, recurring \| Level 1
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total Assets	10,694	8,505
Fair value, measurements, recurring \| Level 1 \| Corporate bonds
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale investment securities:	0	0
Fair value, measurements, recurring \| Level 1 \| Agency securities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale investment securities:	0	0
Fair value, measurements, recurring \| Level 1 \| Certificates of deposit
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale investment securities:		2,981
Fair value, measurements, recurring \| Level 1 \| Money market funds
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Cash equivalents:	10,694	5,524
Fair value, measurements, recurring \| Level 2
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total Assets	27,887	49,220
Fair value, measurements, recurring \| Level 2 \| Corporate bonds
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale investment securities:	23,557	38,217
Fair value, measurements, recurring \| Level 2 \| Agency securities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale investment securities:	4,330	11,003
Fair value, measurements, recurring \| Level 2 \| Certificates of deposit
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale investment securities:		0
Fair value, measurements, recurring \| Level 2 \| Money market funds
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Cash equivalents:	0	0
Fair value, measurements, recurring \| Level 3
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total Assets	0	0
Fair value, measurements, recurring \| Level 3 \| Corporate bonds
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale investment securities:	0	0
Fair value, measurements, recurring \| Level 3 \| Agency securities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale investment securities:	0	0
Fair value, measurements, recurring \| Level 3 \| Certificates of deposit
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale investment securities:		0
Fair value, measurements, recurring \| Level 3 \| Money market funds
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Cash equivalents:	$ 0	$ 0

Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Gross property and equipment	$ 15,913	$ 13,440
Less: Accumulated depreciation	(9,042)	(6,744)
Total property and equipment, net	6,871	6,696
Depreciation expense on property and equipment	2,400	2,300	$ 2,300
Data center and computer equipment
Property, Plant and Equipment [Line Items]
Gross property and equipment	6,854	5,233
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Gross property and equipment	2,928	2,415
Office equipment
Property, Plant and Equipment [Line Items]
Gross property and equipment	798	763
Leasehold improvements
Property, Plant and Equipment [Line Items]
Gross property and equipment	5,254	5,029
Construction in process
Property, Plant and Equipment [Line Items]
Gross property and equipment	$ 79	$ 0

Internal-Use Software Development Costs - Software Development Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Research and Development [Abstract]
Internal use software development costs, gross	$ 58,237	$ 44,626
Less: Accumulated amortization	(37,752)	(27,017)
Internal use software development costs, net	20,485	17,609
Capitalized software development costs during the period	13,800	11,100	$ 11,800
Amortization expense with respect to software development costs during the period	$ 11,000	$ 9,000	$ 6,200

Internal-Use Software Development Costs - Amortization Expense (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2019	$ 10,664
2020	6,848
2021	2,950
2022	23
Internal use software development costs, net	$ 20,485	$ 17,609

Goodwill and Intangible Assets - Goodwill (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill as of December 31, 2017	$ 6,737
Goodwill from acquisition of WegoWise	8,811
Goodwill as of December 31, 2018	$ 15,548

Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 13,169	$ 7,809
Accumulated Amortization	(7,274)	(6,084)
Net Carrying Value	$ 5,895	$ 1,725
Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life in Years	7 years 4 days	5 years 10 months 28 days
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 1,960	$ 790
Accumulated Amortization	(728)	(538)
Net Carrying Value	$ 1,232	$ 252
Customer relationships \| Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life in Years	5 years	5 years
Database
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 3,620
Accumulated Amortization	(121)
Net Carrying Value	$ 3,499
Database \| Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life in Years	10 years
Technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 4,811	$ 4,811
Accumulated Amortization	(4,506)	(3,871)
Net Carrying Value	$ 305	$ 940
Technology \| Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life in Years	8 years	6 years
Trademarks and trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 1,300	$ 930
Accumulated Amortization	(642)	(539)
Net Carrying Value	$ 658	$ 391
Trademarks and trade names \| Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life in Years	9 years	9 years
Partner relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 680	$ 680
Accumulated Amortization	(680)	(623)
Net Carrying Value	$ 0	$ 57
Partner relationships \| Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life in Years	3 years	3 years
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 100	$ 40
Accumulated Amortization	(44)	(37)
Net Carrying Value	$ 56	$ 3
Non-compete agreements \| Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life in Years	4 years	3 years
Domain names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 273	$ 273
Accumulated Amortization	(273)	(273)
Net Carrying Value	$ 0	$ 0
Domain names \| Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life in Years	5 years	5 years
Patents
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 285	$ 285
Accumulated Amortization	(233)	(203)
Net Carrying Value	$ 52	$ 82
Patents \| Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life in Years	5 years	5 years
Backlog
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 140
Accumulated Amortization	(47)
Net Carrying Value	$ 93
Backlog \| Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life in Years	1 year

Goodwill and Intangible Assets - Amortization Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 1,200	$ 1,400	$ 1,400
2019	1,091
2020	904
2021	769
2022	706
2023	563
Thereafter	1,862
Net Carrying Value	$ 5,895	$ 1,725

Long-term Debt (Details)			12 Months Ended
Long-term Debt (Details)	Dec. 24, 2018 USD ($)	Oct. 09, 2015 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Mar. 16, 2015 USD ($)
Debt Instrument [Line Items]
Long-term debt - current portion			$ (1,213,000)	$ 0
Long-term debt, net			48,602,000	0
Long-term Debt, Fiscal Year Maturity [Abstract]
Capitalized deferred financing costs		$ 200,000	500,000	200,000
Amortization of deferred financing costs			(60,000)	(63,000)	$ (63,000)
Other Assets
Long-term Debt, Fiscal Year Maturity [Abstract]
Capitalized deferred financing costs			300,000	200,000
Term Loan
Long-term Debt, Fiscal Year Maturity [Abstract]
Line of credit, amount outstanding						$ 10,000,000.0
Revolving Credit Facility \| Wells Fargo
Long-term Debt, Fiscal Year Maturity [Abstract]
Line of credit, amount outstanding						2,500,000.0
Credit Facility
Long-term Debt, Fiscal Year Maturity [Abstract]
Capitalized deferred financing costs	$ 400,000
EBITDA to interest expense ratio	3.0
Funded indebtedness to EBITDA ratio	3.5
Annual decrease in required leverage ratio	0.25
Required leverage ratio	2.5
Floor plus 20% of the sum of the combined outstanding principal amounts	$ 20,000,000
Acquisition purchase price floor for 0.5 increase in required leverage ratio for 12 month period following the close date	$ 20,000,000.0
Credit Facility \| Federal Funds Rate
Long-term Debt, Fiscal Year Maturity [Abstract]
Variable rate, basis spread percent	1.00%
Credit Facility \| Federal Funds Rate \| Minimum
Long-term Debt, Fiscal Year Maturity [Abstract]
Variable rate, basis spread percent	0.50%
Credit Facility \| Federal Funds Rate \| Maximum
Long-term Debt, Fiscal Year Maturity [Abstract]
Variable rate, basis spread percent	1.00%
Credit Facility \| LIBOR
Long-term Debt, Fiscal Year Maturity [Abstract]
Variable rate, basis spread percent	2.00%
Credit Facility \| LIBOR \| Minimum
Long-term Debt, Fiscal Year Maturity [Abstract]
Variable rate, basis spread percent	1.50%
Credit Facility \| LIBOR \| Maximum
Long-term Debt, Fiscal Year Maturity [Abstract]
Variable rate, basis spread percent	2.00%
Credit Facility \| Term Loan
Debt Instrument [Line Items]
Principal amounts due under term loan			50,000,000
Less: Debt financing costs			185,000
Long-term debt, net of unamortized debt financing costs			49,815,000
Long-term debt - current portion			(1,213,000)
Long-term debt, net			48,602,000
Long-term Debt, Fiscal Year Maturity [Abstract]
2019			1,250,000
2020			1,250,000
2021			2,500,000
2022			2,500,000
2023			42,500,000
Principal amounts due under term loan			50,000,000
Line of credit, amount outstanding	$ 50,000,000					$ 10,000,000
Capitalized deferred financing costs	200,000		185,000	0
Amortization of deferred financing costs			0
Credit Facility \| Revolving Credit Facility
Debt Instrument [Line Items]
Less: Debt financing costs			185,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Maximum borrowing capacity	50,000,000.0
Commitment fee percentage rate, if greater than $10 million		0.25%
Revolving facility benchmark for commitment fees		$ 10,000,000.0
Commitment fee percentage rate, if less than $10 million		0.375%
Capitalized deferred financing costs	$ 200,000	$ 100,000		$ 175,000
Commitment fee percentage	25.00%
Commitment fee, usage threshold for 37.5 basis points commitment fee, percentage	$ 30,000,000
Amortization of deferred financing costs			$ (60,000)
Credit Facility \| Revolving Credit Facility \| Federal Funds Rate
Long-term Debt, Fiscal Year Maturity [Abstract]
Variable rate, basis spread percent		0.50%
Credit Facility \| Revolving Credit Facility \| One-Month LIBOR
Long-term Debt, Fiscal Year Maturity [Abstract]
Variable rate, basis spread percent		1.00%
Credit Facility \| Revolving Credit Facility \| Prime Rate
Long-term Debt, Fiscal Year Maturity [Abstract]
Variable rate, basis spread percent		1.50%
Credit Facility \| Revolving Credit Facility \| LIBOR
Long-term Debt, Fiscal Year Maturity [Abstract]
Variable rate, basis spread percent		2.50%
Credit Facility \| Revolving Credit Facility \| Wells Fargo
Long-term Debt, Fiscal Year Maturity [Abstract]
Maximum borrowing capacity		$ 25,000,000.0
Potential increase to maximum borrowing capacity		$ 10,000,000.0

Commitment and Contingencies - Future Minimum Operating Lease Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jul. 27, 2018
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019	$ 4,211
2020	4,889
2021	4,038
2022	2,717
2023	2,053
Thereafter	9,128
Total lease commitments	$ 27,036	$ 16,600

Commitment and Contingencies - Additional Information (Details) ft² in Thousands		12 Months Ended
	Jul. 27, 2018 USD ($) ft² extension_term	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2018 USD ($)
Loss Contingencies [Line Items]
Rent expense		$ 2,600,000	$ 2,100,000	$ 2,000,000
Area of office space rented \| ft²	86
Lease term	10 years
Number of lease term extensions \| extension_term	2
Lease renewable term	5 years
Base rent, 60% of premises	$ 80,000
Base rent, 80% of premises	107,000
Base rent, 100% of premises	$ 134,000
Base rent, annual increase percent	3.00%
Total lease commitments	$ 16,600,000	27,036,000
Per incident policy limit		$ 100,000
Quota share of tenant liability insurance provided, percent		100.00%
Deposits held with a third party related to insurance services collateral		$ 1,100,000
Other current liabilities
Loss Contingencies [Line Items]
Liability for reported claims and claims incurred but not reported		600,000	500,000
Other current assets
Loss Contingencies [Line Items]
Deposits held with a third party related to insurance services collateral		$ 1,800,000	$ 1,800,000
Lease on 90 Castilian Drive, Santa Barbara, California
Loss Contingencies [Line Items]
Number of lease term extensions \| extension_term	2
Lease renewable term	3 years
Total lease commitments	$ 1,800,000
Lease on 7300 Lone Star Drive in Plano, Texas
Loss Contingencies [Line Items]
Lease term					24 months
Lessee, Operating Lease, Monthly Expense					$ 61,000

Stockholders' Equity - Amended and Restated Certificate of Incorporation (Details) - $ / shares	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jun. 25, 2015
Class of Stock [Line Items]
Capital stock, shares authorized					325,000,000
Preferred stock, shares authorized					25,000,000
Preferred stock, shares outstanding					0
Class A common stock
Class of Stock [Line Items]
Common stock, shares authorized	250,000,000	250,000,000
Common stock, par value (usd per share)	$ 0.0001	$ 0.0001
Class B common stock
Class of Stock [Line Items]
Common stock, shares authorized	50,000,000	50,000,000
Common stock, par value (usd per share)	$ 0.0001	$ 0.0001
Common stock \| Class A common stock
Class of Stock [Line Items]
Common stock, shares authorized					250,000,000
Common stock, par value (usd per share)					$ 0.0001
Common stock, shares outstanding	15,789,000	14,879,000	11,691,000	9,005,000
Common stock \| Class B common stock
Class of Stock [Line Items]
Common stock, shares authorized					50,000,000
Common stock, par value (usd per share)					$ 0.0001
Common stock, shares outstanding	18,109,000	19,102,000	22,028,000	24,541,000
Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized					25,000,000
Preferred stock, shares outstanding	0

Stockholders' Equity - Class A Common Stock and Class B Common Stock, Reverse Stock Split (Details)	12 Months Ended
	Dec. 31, 2018 vote
Common Class B To Common Class A
Class of Stock [Line Items]
Number of shares to be issued per share upon conversion	1
Number of shares to be issued per share upon automatic conversion	1
Automatic conversion threshold as a percent of Class B common stock	10.00%
Class A common stock
Class of Stock [Line Items]
Common stock, number of votes	1
Class B common stock
Class of Stock [Line Items]
Common stock, number of votes	10

Stockholders' Equity - Preferred Stock (Details) - USD ($) $ in Thousands	2 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Oct. 31, 2018	Jun. 25, 2015
Equity [Abstract]
Preferred stock, shares outstanding				0
Preferred stock, shares authorized				25,000,000
Number of shares authorized for repurchase			30,000,000.0
Number of shares repurchased during period	370,751
Repurchase of common stock	$ 21,600	$ 21,562

Income Taxes - Effective Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income tax expense	$ 420	$ 58	$ 67
Income tax benefit at the statutory rate	21.00%	34.00%	34.00%
State and local income taxes, net of federal benefit	(3.00%)	(14.00%)	7.00%
Stock-based compensation expense	(7.00%)	(15.00%)	(4.00%)
Meals and entertainment	1.00%	2.00%	(2.00%)
Permanent differences	0.00%	0.00%	(1.00%)
Change in valuation allowance	(1.00%)	(60.00%)	(42.00%)
Change in federal rate	0.00%	74.00%	0.00%
Research and development tax credits	(9.00%)	(20.00%)	7.00%
Provision for income taxes	2.00%	1.00%	(1.00%)

Income Taxes - Components of Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current
Federal	$ 0	$ 0	$ 0
State and Local	339	53	24
Current Income Tax Expense	339	53	24
Deferred
Federal	65	(2)	40
State and Local	16	7	3
Deferred Income tax (benefit) expense	81	5	43
Total income tax provision	$ 420	$ 58	$ 67

Income Taxes - Components of Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred income tax assets:
Net operating loss carryforwards	$ 15,675	$ 19,519
Research and development tax credits	11,907	8,278
Intangible assets	143	0
Stock-based compensation	2,203	1,543
Other	2,878	950
Gross deferred tax assets	32,806	30,290
Valuation allowance	(23,002)	(23,827)	$ (29,417)	$ (25,926)
Deferred tax assets, net of valuation allowance	9,804	6,463
Deferred tax liabilities:
Property, equipment and software	(5,464)	(4,293)
Intangible assets	0	(6)
Capitalized commissions	(1,825)	0
State taxes	(1,935)	(1,693)
Other	(739)	(549)
Total deferred tax liabilities	(9,963)	(6,541)
Total net deferred tax liabilities	(159)	$ (78)
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	57,700
Federal \| Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Credit carryforwards	7,400
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	41,200
State \| Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Credit carryforwards	$ 7,500

Income Taxes - Changes in Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Changes In Valuation Allowance [Roll Forward]
Valuation allowance, at beginning of year	$ 23,827	$ 29,417	$ 25,926
Increase (decrease) in valuation allowance	(825)	(5,590)	3,491
Valuation allowance, at end of year	$ 23,002	$ 23,827	$ 29,417

Income Taxes - Unrecognized Tax Benefits (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefit beginning of year	$ 2,105,000	$ 4,032,000	$ 2,867,000
Decreases-tax positions in prior year	0	(2,210,000)	0
Increases-tax positions in current year	872,000	283,000	1,165,000
Unrecognized tax benefit end of year	2,977,000	2,105,000	$ 4,032,000
Income tax examination, penalties and interest accrued	$ 0	$ 0

Stock-Based Compensation - Stock Option Plans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options exercisable (shares)	31,000	1,034,000
Options exercisable, weighted average exercise price (usd per share)		$ 8.82
Options outstanding (shares)	1,513,000	1,693,000
Options granted (in shares)	0
Options canceled/forfeited (shares)	(10,000)
Intrinsic value of options exercised	$ 7,500,000	$ 4,600,000	$ 1,900,000
Intrinsic value of options outstanding	72,500,000
Intrinsic value of exercisable options	52,100,000
Instrinsic value of options	72,400,000
Excess tax benefit	$ 5,200,000	$ 200,000
Early exercisable stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options exercisable, weighted average exercise price (usd per share)	$ 5.64
Stock-based compensation expense, weighted average recognition period (in years)	6 years 1 month 6 days
Employee Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)		172,000	750,000
Stock-based compensation expense	$ 1,600,000	$ 2,900,000	$ 2,400,000
Employee Stock Options and Performance Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense, weighted average recognition period (in years)	8 months 27 days
Compensation for unvested stock options	$ 700,000
2015 Stock Incentive Plan \| Employee Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term of stock options granted				10 years
2019 and 2018 Performance Metric Granted in 2017 \| PSOs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding (shares)	172,000
2019 Performance Metric \| PSOs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)	40,000
2019 Performance Metric \| PSOs \| PSUs to vest based on Employee Performance, maximum 150%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percent of awards granted	110.00%
Percent of award target performance metric	50.00%
2019 Performance Metric \| PSOs \| PSUs to vest based on Employee performance, 80%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percent of awards granted	115.00%
Percent of award target performance metric	50.00%
2019 Performance Metric, Targeted Free Cash Flow Performance Metric \| PSOs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)	132,000
Vesting percent of awards granted	150.00%
Percent of award target performance metric	100.00%
2017 and 2018 Performance Metric \| PSOs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding (shares)	250,000
Options granted (in shares)	250,000
Percent of award target performance metric	150.00%
2017 Performance Metric, Targeted Free Cash Flow Performance Metric \| PSOs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
PSOs vested (in shares)	250,000
Percent of achievement of award target performance metric	150.00%
2017 Performance Metric \| PSOs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 0
Class A common stock \| 2015 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate number of shares reserved for stock incentive plan	3,791,744			2,000,000
Class B common stock \| 2007 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of additional shares authorized	532,978

Stock-Based Compensation - Stock Option Activity (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Number of Shares
Options outstanding, beginning balance (shares)	1,693
Options granted (in shares)	0
Options exercised (shares)	(170)
Options canceled/forfeited (shares)	(10)
Options outstanding, ending balance (shares)	1,513	1,693
Options vested of expected to vest (shares)		1,513
Options exercisable (shares)	31	1,034
Weighted Average Exercise Price per Share
Options outstanding, beginning balance (usd per share)	$ 10.81
Options granted (usd per share)	0.00
Options exercised (usd per share)	6.09
Options canceled/forfeited (usd per share)	15.09
Options outstanding, ending balance (usd per share)	$ 11.31	$ 10.81
Options vested and expected to vest, weighted average exercise price (usd per share)		11.32
Options exercisable, weighted average exercise price (usd per share)		$ 8.82
Options outstanding, weighted average remaining contractual life (in years)	6 years 4 months 24 days	7 years 3 months 18 days
Options vested or expected to vest, weighted average remaining contractual life (in years)	6 years 8 months 12 days
Options exercisable, weighted average remaining contractual life (in years)	6 years 4 months 24 days

Stock-Based Compensation - Valuation Assumptions (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted	0
Weighted average exercise price (dollars per share)	$ 0.00
Employee Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted		172	750
Weighted average exercise price (dollars per share)		$ 24.77	$ 12.85
Weighted average grant-date fair value (dollars per share)		$ 9.58	$ 4.85
Weighted average Black-Scholes model assumptions:
Risk-free interest rate		2.02%	1.45%
Expected term (in years)		6 years 4 months 24 days	5 years 10 months 24 days
Expected volatility		35.00%	37.00%
Expected dividend yield		0.00%	0.00%

Stock-Based Compensation - Restricted Stock Units (Details) - RSUs and PSUs	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Number of Shares
Unvested, beginning balance (shares) \| shares	598,000
Granted (shares) \| shares	305,000
Vested (shares) \| shares	(180,000)
Forfeited (shares) \| shares	(49,000)
Unvested, ending balance (shares) \| shares	674,000
Weighted- Average Grant Date Fair Value per Share
Unvested, beginning balance (usd per share) \| $ / shares	$ 19.75
Granted (usd per share) \| $ / shares	48.12
Vested (usd per share) \| $ / shares	17.89
Forfeited (usd per share) \| $ / shares	26.05
Unvested, ending balance (usd per share) \| $ / shares	$ 32.61

Stock-Based Compensation - Restricted Stock Units Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
RSUs and PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)		305,000
Shares vested		180,000
Stock-based compensation expense		$ 5,500	$ 3,600	$ 1,800
Remaining stock-based compensation expense for unvested shares, not yet recognized		$ 15,000
Stock-based compensation expense, weighted average recognition period (in years)		2 years 2 months 1 day
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)		188,000
Vesting period	4 years	4 years
PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)		102,000
Percent of award target performance metric		100.00%
Shares vested		30,000
Percent of achievement of award target performance metric			150.00%
PSUs \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of award target performance metric		0.00%
PSUs \| Minimum \| PSUs to vest based on Employee Performance, maximum 150%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of award target performance metric		100.00%
Performance-based cash bonus payment, percent		100.00%
PSUs \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of award target performance metric		100.00%
PSUs \| Maximum \| PSUs to vest based on Employee Performance, maximum 150%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of award target performance metric		150.00%
Performance-based cash bonus payment, percent		165.00%
PSUs \| 2017 Performance Metric
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)		15,000
PSUs \| 2016 Performance Metric
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)			15,000
Unvested RSAs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)		5,000
Shares vested		15,000
Stock-based compensation expense		$ 335	$ 358	$ 454
Remaining stock-based compensation expense for unvested shares, not yet recognized		$ 100
Stock-based compensation expense, weighted average recognition period (in years)		6 months
Fair value of shares vested		$ 335
Unvested RSAs \| Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years
Unvested RSAs \| Non-Employee Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		1 year
Performance Stock Units Granted in 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)		91,000
Performance Stock Units Granted in 2017 \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of award target performance metric		0.00%
Performance Stock Units Granted in 2017 \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of award target performance metric		165.00%
Performance Stock Units Granted in 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)		26,000
Performance Stock Units Granted in 2016 \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of award target performance metric		0.00%
Performance Stock Units Granted in 2016 \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of award target performance metric		150.00%

Stock-Based Compensation - Restricted Stock Awards (Details) - RSAs shares in Thousands	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Number of Shares
Unvested, beginning balance (shares) \| shares	16
Granted (shares) \| shares	5
Vested (shares) \| shares	(15)
Forfeited (shares) \| shares	0
Unvested, ending balance (shares) \| shares	6
Weighted- Average Grant Date Fair Value per Share
Unvested, beginning balance (usd per share) \| $ / shares	$ 20.93
Granted (usd per share) \| $ / shares	61.05
Vested (usd per share) \| $ / shares	21.97
Forfeited (usd per share) \| $ / shares	0.00
Unvested, ending balance (usd per share) \| $ / shares	$ 51.36

Revenue and Other Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Product Information [Line Items]
Revenue	$ 190,071	$ 143,803	$ 105,586
Core solutions
Product Information [Line Items]
Revenue	70,549	57,132	43,775
Value plus services
Product Information [Line Items]
Revenue	113,072	80,847	56,965
Other
Product Information [Line Items]
Revenue	$ 6,450	$ 5,824	$ 4,846

Retirement Plans (Details) - USD ($) $ in Millions	12 Months Ended
Retirement Plans (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
401k cash contributions	$ 1.6	$ 0.8	$ 1.1

Subsequent Events (Details)			2 Months Ended	4 Months Ended	12 Months Ended
Subsequent Events (Details)	Feb. 20, 2019 USD ($) director	Jan. 07, 2019 USD ($)	Dec. 31, 2018 USD ($) shares	Feb. 20, 2019 USD ($) shares	Dec. 31, 2018 USD ($)	Oct. 31, 2018 USD ($)
Subsequent Event [Line Items]
Authorized amount under share repurchase program						$ 30,000,000.0
Number of shares repurchased during period \| shares			370,751
Repurchase of common stock			$ 21,600,000		$ 21,562,000
Subsequent Event
Subsequent Event [Line Items]
Authorized amount under share repurchase program	$ 100,000,000.0			$ 100,000,000.0
Number of directors to authorized repurchases \| director	3
Number of shares repurchased during period \| shares				370,751
Repurchase of common stock				$ 21,600,000
Remaining authorized amount under share repurchase program	$ 8,400,000			$ 8,400,000
Subsequent Event \| Merger Subsidiary
Subsequent Event [Line Items]
Merger consideration		$ 60,200,000
Merger consideration, holdback amount		$ 6,000,000