Avalara (AVLR) 10-K 28 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Feb. 22, 2019	Jun. 29, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Trading Symbol	AVLR
Entity Registrant Name	AVALARA, INC.
Entity Central Index Key	1,348,036
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Extended Transition Period	false
Entity Common Stock, Shares Outstanding		69,470,575
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Public Float			$ 1,760
Entity Shell Company	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 142,322	$ 14,075
Trade accounts receivable—net of allowance for doubtful accounts of $521 and $905, respectively	40,287	26,596
Prepaid expenses and other current assets	11,307	7,016
Total current assets before customer fund assets	193,916	47,687
Funds held from customers	13,113	13,082
Receivable from customers—net of allowance of $198 and $666, respectively	270	313
Total current assets	207,299	61,082
Noncurrent assets:
Property and equipment—net	33,373	25,394
Goodwill	61,300	72,482
Intangible assets—net	19,371	19,074
Other noncurrent assets	1,589	780
Total assets	322,932	178,812
Current liabilities:
Accrued expenses and trade payables	47,064	38,164
Deferred revenue	125,260	83,778
Credit facility and notes payable		859
Total current liabilities before customer funds obligations	172,324	122,801
Customer funds obligations	13,349	14,061
Total current liabilities	185,673	136,862
Noncurrent liabilities:
Deferred revenue	9,393	8,453
Deferred tax liability	560	1,854
Credit facility		38,840
Deferred rent	17,317	14,689
Other noncurrent liabilities	436	785
Total liabilities	213,379	201,483
Commitments and contingencies
Shareholders' equity (deficit):
Preferred stock, $0.0001 par value– no shares issued and outstanding at December 31, 2018 and December 31, 2017, and 20,000 shares authorized as of December 31, 2018	0	0
Common stock, $0.0001 par value– 66,769 and 5,992 shares issued and outstanding at December 31, 2018 and December 31, 2017, respectively, 600,000 and 153,945 shares authorized as of December 31, 2018 and December 31, 2017, respectively	7	1
Additional paid-in capital	599,493	18,121
Accumulated other comprehensive income (loss)	(2,345)	338
Accumulated deficit	(487,602)	(412,052)
Total shareholders’ equity (deficit)	109,553	(393,592)
Total liabilities and shareholders' equity (deficit)	$ 322,932	178,812
Series A Convertible Preferred Stock
Convertible preferred stock:
Convertible preferred stock		12,715
Series A-1 Convertible Preferred Stock
Convertible preferred stock:
Convertible preferred stock		2,081
Series A-2 Convertible Preferred Stock
Convertible preferred stock:
Convertible preferred stock		303
Series B Convertible Preferred Stock
Convertible preferred stock:
Convertible preferred stock		3,756
Series B-1 Convertible Preferred Stock
Convertible preferred stock:
Convertible preferred stock		23,259
Series C Convertible Preferred Stock
Convertible preferred stock:
Convertible preferred stock		19,782
Series C-1 Convertible Preferred Stock
Convertible preferred stock:
Convertible preferred stock		27,961
Series D Convertible Preferred Stock
Convertible preferred stock:
Convertible preferred stock		41,130
Series D-1 Convertible Preferred Stock
Convertible preferred stock:
Convertible preferred stock		143,915
Series D-2 Convertible Preferred Stock
Convertible preferred stock:
Convertible preferred stock		$ 96,019

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Trade accounts receivable, allowance for doubtful accounts	$ 521	$ 905
Receivable from customers, allowance	$ 198	$ 666
Convertible preferred stock, par value		$ 0.0001
Convertible preferred stock, shares issued	0
Convertible preferred stock, shares outstanding	0
Convertible preferred stock, shares authorized	0	106,346,091
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Preferred stock, shares authorized	20,000,000	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares, issued	66,769,000	5,992,000
Common stock, shares, outstanding	66,769,000	5,992,000
Common stock, shares authorized	600,000,000	153,945,000
Series A Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	12,309,000
Convertible preferred stock, shares outstanding	0	12,309,000
Convertible preferred stock, shares authorized	0	13,814,000
Convertible preferred stock, aggregate liquidation preference		$ 10,930
Series A-1 Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	4,688,000
Convertible preferred stock, shares outstanding	0	4,688,000
Convertible preferred stock, shares authorized	0	5,012,000
Convertible preferred stock, aggregate liquidation preference		$ 2,081
Series A-2 Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	279,000
Convertible preferred stock, shares outstanding	0	279,000
Convertible preferred stock, shares authorized	0	279,000
Convertible preferred stock, aggregate liquidation preference		$ 472
Series B Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	1,793,000
Convertible preferred stock, shares outstanding	0	1,793,000
Convertible preferred stock, shares authorized	0	2,133,000
Convertible preferred stock, aggregate liquidation preference		$ 1,685
Series B-1 Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	21,518,000
Convertible preferred stock, shares outstanding	0	21,518,000
Convertible preferred stock, shares authorized	0	21,600,000
Convertible preferred stock, aggregate liquidation preference		$ 23,670
Series C Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	7,069,000
Convertible preferred stock, shares outstanding	0	7,069,000
Convertible preferred stock, shares authorized	0	7,069,000
Convertible preferred stock, aggregate liquidation preference		$ 20,000
Series C-1 Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	8,511,000
Convertible preferred stock, shares outstanding	0	8,511,000
Convertible preferred stock, shares authorized	0	8,590,000
Convertible preferred stock, aggregate liquidation preference		$ 12,767
Series D Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	8,566,000
Convertible preferred stock, shares outstanding	0	8,566,000
Convertible preferred stock, shares authorized	0	10,172,000
Convertible preferred stock, aggregate liquidation preference		$ 44,972
Series D-1 Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	22,808,000
Convertible preferred stock, shares outstanding	0	22,808,000
Convertible preferred stock, shares authorized	0	22,862,000
Convertible preferred stock, aggregate liquidation preference		$ 144,147
Series D-2 Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	14,245,000
Convertible preferred stock, shares outstanding	0	14,245,000
Convertible preferred stock, shares authorized	0	14,815,000
Convertible preferred stock, aggregate liquidation preference		$ 96,154

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue:
Subscription and returns	$ 254,056	$ 199,942	$ 154,967
Professional services	18,042	13,217	12,459
Total revenue	272,098	213,159	167,426
Cost of revenue:
Subscription and returns	66,556	48,849	41,307
Professional services	12,093	9,128	7,206
Total cost of revenue	78,649	57,977	48,513
Gross profit	193,449	155,182	118,913
Operating expenses:
Research and development	51,909	41,264	32,848
Sales and marketing	168,817	133,794	103,483
General and administrative	39,603	34,286	36,875
Restructuring charges	0	752	0
Goodwill impairment	9,174	8,418	0
Total operating expenses	269,503	218,514	173,206
Operating loss	(76,054)	(63,332)	(54,293)
Other (income) expense:
Interest income	(1,553)	(77)	(18)
Interest expense	2,608	2,585	2,301
Other (income) expense, net	(583)	(495)	672
Total other (income) expense, net	472	2,013	2,955
Loss before income taxes	(76,526)	(65,345)	(57,248)
Provision for (benefit from) income taxes	(976)	(1,219)	640
Net loss	$ (75,550)	$ (64,126)	$ (57,888)
Net loss per share attributable to common shareholders, basic and diluted	$ (1.95)	$ (11.39)	$ (10.15)
Weighted average shares of common stock outstanding, basic and diluted	38,692	5,632	5,706

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (75,550)	$ (64,126)	$ (57,888)
Other comprehensive income (loss)—Foreign currency translation	(2,683)	1,806	(634)
Total comprehensive loss	$ (78,233)	$ (62,320)	$ (58,522)

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock and Shareholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Other Comprehensive Income (Loss)	Accumulated Deficit	Convertible Preferred Shares
Balance at Dec. 31, 2015						$ 283,640
Balance, shares at Dec. 31, 2015						91,215,962
Issuance of preferred stock-net of issuance costs						$ 96,019
Issuance of preferred stock-net of issuance cost, shares						14,244,640
Exercise of warrants						$ 2,188
Exercise of warrants, shares						315,315
Repurchase of shares						$ (10,926)
Repurchase of shares, shares						(3,989,712)
Balance at Dec. 31, 2016						$ 370,921
Balance, shares at Dec. 31, 2016						101,786,205
Balance at Dec. 31, 2015	$ (263,264)	$ 1	$ 7,013	$ (834)	$ (269,444)
Balance, shares at Dec. 31, 2015		5,643,959
Exercise of stock options	2,645		2,645
Exercise of stock options, shares		878,017
Exercise of warrants	99		99
Exercise of warrants, shares		71,250
Stock-based compensation expense	8,139		8,139
Repurchase of shares	(36,022)		(15,538)		(20,484)
Repurchase of shares, shares		(1,581,107)
Stock issuance for acquisitions	3,764		3,764
Stock issuance for acquisitions, shares		285,714
Gain (Loss) on translation adjustment	(634)			(634)
Net loss	(57,888)				(57,888)
Balance at Dec. 31, 2016	(343,161)	$ 1	6,122	(1,468)	(347,816)
Balance, shares at Dec. 31, 2016		5,297,833
Balance at Dec. 31, 2017						$ 370,921
Balance, shares at Dec. 31, 2017						101,786,205
Shares tendered for cashless redemption	(2,481)		(2,481)
Shares tendered for cashless redemption, shares		(167,250)
Exercise of stock options	2,283		2,283
Exercise of stock options, shares		593,698
Exercise of warrants	308		308
Exercise of warrants, shares		268,012
Stock-based compensation expense	11,779		11,779
Gain (Loss) on translation adjustment	1,806			1,806
Cumulative adjustment ASU 2016-09			110		(110)
Net loss	(64,126)				(64,126)
Balance at Dec. 31, 2017	$ (393,592)	$ 1	18,121	338	(412,052)
Balance, shares at Dec. 31, 2017	5,992,000	5,992,293
Conversion of preferred stock to common stock	$ 370,854	$ 5	370,849			$ (370,854)
Conversion of preferred stock to common stock, shares		50,888,014				(101,776,205)
Repurchase of shares						$ (67)
Repurchase of shares, shares						(10,000)
Balance, shares at Dec. 31, 2018	0
Proceeds from initial public offering, net of underwriters' discounts	$ 192,510	$ 1	192,509
Proceeds from initial public offering, net of underwriters' discounts, shares		8,625,000
Stock issuance costs	(3,425)		(3,425)
Shares tendered for cashless redemption	(11,589)		(11,589)
Shares tendered for cashless redemption, shares		(613,567)
Exercise of stock options	$ 10,478		10,478
Exercise of stock options, shares	1,373,962	1,373,962
Exercise of warrants	$ 5,783		5,783
Exercise of warrants, shares		570,000
Stock-based compensation expense	15,950		15,950
Repurchase of shares	(1,738)		(1,738)
Repurchase of shares, shares		(104,847)
Gain (Loss) on translation adjustment	(2,683)			(2,683)
Shares issued to purchase intangible assets	2,555		2,555
Shares issued to purchase intangible assets, shares		37,708
Net loss	(75,550)				(75,550)
Balance at Dec. 31, 2018	$ 109,553	$ 7	$ 599,493	$ (2,345)	$ (487,602)
Balance, shares at Dec. 31, 2018	66,769,000	66,768,563

Consolidated Statements of Co_2

Consolidated Statements of Convertible Preferred Stock and Shareholders' Equity (Deficit) (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Convertible Preferred Shares
Issuance of preferred stock, issuance cost	$ 133

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net loss	$ (75,550)	$ (64,126)	$ (57,888)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	12,802	10,859	10,425
Goodwill impairment	9,174	8,418	0
Stock-based compensation	15,921	11,757	8,112
Deferred tax expense	(1,294)	(1,307)	134
Amortization of deferred rent	190	(698)	789
Non-cash change in earnout liability	(402)	(715)	361
Change in preferred stock warrant liability			(28)
Non-cash bad debt (recovery) expense	(288)	(86)	2,907
Other	559	270	368
Changes in operating assets and liabilities:
Trade accounts receivable	(13,508)	159	(11,143)
Prepaid expenses and other current assets	(4,850)	(1,055)	(29)
Other long-term assets	(808)	725	802
Trade payables	(4,419)	(112)	2,853
Accrued expenses and other current liabilities	15,266	2,124	4,414
Deferred rent (lease incentives)	1,723	10,494
Deferred revenue	42,422	19,752	16,227
Net cash used in operating activities	(3,062)	(3,541)	(21,696)
Cash flows from investing activities:
Net (increase) decrease in customer fund assets	118	(2,301)	(5,816)
Cash paid for acquired intangible assets	(5,002)
Cash paid for acquisitions—net of cash acquired			(17,218)
Purchase of property and equipment	(15,483)	(13,955)	(6,660)
Net cash used in investing activities	(20,367)	(16,256)	(29,694)
Cash flows from financing activities:
Proceeds from initial public offering, net of underwriting discounts	192,510
Payments on credit facility	(63,000)	(2,935)	(52,000)
Proceeds from credit facility	23,000	17,605	57,000
Payments of debt issuance costs		(469)	(481)
Payments on capital leases		(14)	(81)
Proceeds from issuance of convertible preferred stock			96,152
Repurchase of shares	(1,806)		(43,185)
Repayment of note payable	(234)
Payments of deferred financing costs	(2,084)	(1,240)
Convertible preferred stock issuance costs			(133)
Taxes paid related to net share settlement of stock-based awards	(2,365)	(811)	(1,776)
Net increase (decrease) in customer fund obligations	(118)	2,301	5,816
Payment related to business combination earnouts	(1,523)	(1,662)	(1,325)
Proceeds from exercise of stock options and common stock warrants	7,041	920	1,013
Net cash provided by financing activities	151,421	13,695	61,000
Foreign currency effect on cash and cash equivalents	255	(53)	(57)
Net change in cash and cash equivalents	128,247	(6,155)	9,553
Cash and cash equivalents—Beginning of year	14,075	20,230	10,677
Cash and cash equivalents—End of year	142,322	14,075	20,230
Supplemental cash flow disclosures:
Cash paid for interest expense	2,495	2,112	2,044
Cash paid for income taxes	390	354	259
Non-cash investing and financing activities:
Stock issued for acquisitions			3,764
Property and equipment purchased under tenant improvement allowance	1,062	250	181
Property and equipment additions in accounts payable and accrued expenses	729	2,201	164
Deferred financing costs, accrued not yet paid	100	335
Shares issued to purchase intangible assets	2,555
Accrued value of earnout related to acquisition	0		663
Cashless exercises of options and warrants	9,224	1,670	1,994
Cashless redemptions of options and warrants	$ 11,589	$ 2,481	$ 1,989

Nature of Operations

Nature of Operations	12 Months Ended
	Dec. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Operations	Avalara, Inc. (the “Company”) provides software solutions that help businesses of all types and sizes comply with tax requirements for transactions worldwide. The Company offers a broad and growing suite of compliance solutions for transaction taxes, such as sales and use tax, value-added tax (VAT), excise tax, lodging tax, and communications tax. These solutions enable customers to automate the process of determining taxability, identifying applicable tax rates, determining and collecting taxes, preparing and filing returns, remitting taxes, maintaining tax records, and managing compliance documents. The Company, a Washington corporation, was originally incorporated in 1999 and is headquartered in Seattle, Washington. The Company has wholly owned subsidiaries in the United Kingdom, Canada, Belgium, India, and Brazil that provide business development, software development, and support services.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Significant Accounting Policies	2. Significant Accounting Policies Initial Public Offering In June 2018, the Company completed an initial public offering (“IPO”), in which the Company sold 8,625,000 shares of its common stock, including the full exercise of the underwriters’ option to purchase 1,125,000 additional shares of common stock, at the initial price to the public of $24.00 per share. The Company received net proceeds of $192.5 million, after deducting underwriting discounts and commissions and before deducting offering expenses paid and payable by the Company of $3.4 million. Immediately prior to the closing of the IPO, (1) all outstanding shares of preferred stock converted into shares of the Company’s common stock on a 2-to-1 basis, and (2) common stock warrants then outstanding were automatically net exercised into shares of the Company’s common stock. As of December 31, 2018, 66,768,563 shares of the Company’s common stock were outstanding. Reverse Stock Split and Conversion of Series Preferred Stock On May 10, 2018, the Company effected a 2-to-1 reverse stock split of outstanding common stock, including outstanding stock options and common stock warrants. At the same time, the Company amended its amended and restated articles of incorporation to trigger the automatic conversion of the Series Preferred Stock immediately prior to the closing of the IPO. As a result of the reverse stock split, the applicable conversion price was increased for each series of outstanding Series Preferred Stock. The increased conversion price effectively resulted in a 2-to-1 conversion ratio of Series Preferred Stock to common stock. All common share and per common share amounts for all periods presented in these consolidated financial statements and notes thereto, have been adjusted retrospectively, where applicable, to reflect the reverse stock split. Series Preferred Stock amounts have been adjusted retrospectively only where the conversion to common stock is presented. Accounting Principles The consolidated financial statements and accompanying notes were prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”). Principles of Consolidation The accompanying consolidated financial statements include those of the Company and its subsidiaries after elimination of all intercompany accounts and transactions. Segments The Company operates its business as one operating segment. Operating segments are defined as components of an enterprise about which separate financial information is evaluated regularly by the chief operating decision maker, the Company’s Chief Executive Officer, in deciding how to allocate resources and assess performance. The Company’s chief operating decision maker allocates resources and assesses performance based upon discrete financial information at the consolidated level. For the years ended December 31, 2018, 2017, and 2016, approximately 6%, 5%, and 3% of the Company’s revenues were generated outside of the United States, respectively. As of December 31, 2018 and 2017, approximately 7% and 11% of the Company’s long-lived assets were held outside of the United States. As of December 31, 2018 and 2017, approximately 3% and 5% of the Company’s long-lived assets were held in the United Kingdom. Use of Estimates The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Significant estimates include: the standalone value of each element in multiple-element arrangements for revenue recognition; the allowance for doubtful accounts; the measurement of fair values of stock-based compensation award grants; the expected earnout obligations in connection with acquisitions; the expected term of the customer relationship for activation, integration, and setup fee activity (collectively, the “setup fee”); the valuation of acquired intangible assets; and the valuation of the fair value of reporting units for analyzing goodwill. Actual results could materially differ from those estimates. Risks and Uncertainties The Company has incurred significant operating losses since its inception, including net losses of $75.6 million, $64.1 million, and $57.9 million for the years ended December 31, 2018, 2017, and 2016, respectively. The Company had an accumulated deficit of $487.6 million and $412.1 million as of December 31, 2018 and 2017, respectively. The Company believes that its cash and cash equivalents of $142.3 million as of December 31, 2018 and the availability under its revolving credit facility, as is further outlined in Note 8, are adequate to satisfy its current obligations. Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. A three-level fair value hierarchy prioritizes the inputs used to measure fair value. The hierarchy requires entities to maximize the use of observable inputs and minimize the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows: • Level 1 • Level 2 • Level 3 The Company’s assessment of the significance of an input to the fair value measurement requires judgment, which may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels. The carrying amounts reported in the consolidated financial statements approximate the fair value for cash equivalents, trade accounts receivable, trade payables, and accrued expenses, due to their short-term nature. The carrying amount of the Company’s term loan and revolving credit facility, to the extent there is a carrying amount as of the balance sheet date, approximates fair value, considering the interest rates are based on the prime interest rate. Cash and Cash Equivalents Cash and cash equivalents include highly liquid securities with original maturities of three months or less and are carried at cost, which approximates market value given their short-term nature. Customer Funds Assets and Obligations Funds Held from Customers The Company maintains trust accounts with financial institutions, which allows customers to outsource their tax remittance functions to the Company. The Company has legal ownership over the accounts utilized for this purpose. Funds held from customers represents cash and cash equivalents that, based upon the Company’s intent, are restricted solely for satisfying the obligations to remit funds relating to the Company’s tax remittance services. Funds held from customers are not commingled with the Company’s operating funds but are typically deposited with funds also held on behalf of other customers of the Company. Funds held from customers are deposited in accounts at FDIC-insured institutions. Funds held from customers were $13.1 million as of both December 31, 2018 and 2017. Receivables from Customers Occasionally, the Company will pay a tax obligation to taxing authorities on behalf of its customer, prior to receiving funds from the customer or prior to receiving the refund due to the customer from the taxing authority. Accounts receivable from customers represent amounts the customer is contractually obligated to repay to the Company. The future economic benefit to the Company is restricted solely for the repayment of customer funds and taxing authority obligations. Receivables from customers deemed uncollectible are charged against a separate allowance for doubtful accounts. The allowance against receivables from customers is a result of the Company assuming credit risk associated with its customers’ tax remittance obligations. The table below details the allowance against receivables from customers (in thousands): December 31, 2018 2017 2016 Balance at the beginning of the year $ 666 $ 754 $ 266 Charged to expense (83 ) (88 ) 517 Write-offs (385 ) - (29 ) Balance at the end of the year $ 198 $ 666 $ 754 Customer Funds Obligations Customer funds obligations represent the Company’s contractual obligations to remit collected funds to satisfy customer tax payments. Customer funds obligations are reported as a current liability on the consolidated balance sheets, as the obligations are expected to be settled within one year. Customer Funds Assets and Obligations in Consolidated Statement of Cash Flows Cash flows related to the cash received from and paid on behalf of customers are reported as follows: (1) changes in customer funds obligations liability are presented as cash flows from financing activities; (2) changes in customer funds asset (e.g., customer funds held in cash and cash equivalents and receivable from customers and taxing authorities) are presented as net cash flows from investing activities; and (3) changes in customer funds asset account that relate to activities paying for the trust operations, such as banking fees, are included as cash flows from operating activities. Trade Accounts Receivable Trade accounts receivable represent amounts due from customers when the Company has invoiced the customer and has not yet received payment. An invoice is issued when the customer is contractually obligated to pay for software subscriptions and/or services. Trade accounts receivable are presented net of an allowance for doubtful accounts. The allowance for doubtful accounts is the Company’s best estimate of the amount of probable credit losses in existing trade accounts receivable. The allowance for doubtful accounts is based on the assessment of collectability. The Company regularly reviews the adequacy of the allowance for doubtful accounts by considering several factors, including the age of each outstanding invoice and the collection history of each customer. Trade accounts receivable are recorded to bad debt expense when deemed uncollectible based on either a specific identification or the age of the receivable. The table below details the allowance for doubtful accounts (in thousands): December 31, 2018 2017 2016 Balance at the beginning of the year $ 905 $ 1,324 $ 1,154 Charged to expense (183 ) (105 ) 2,390 Write-offs (201 ) (314 ) (2,220 ) Balance at the end of the year $ 521 $ 905 $ 1,324 Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk are primarily cash, cash equivalents, accounts receivable, and funds held from customers, which are held in financial institutions management believes have a high credit standing. To manage credit risk related to accounts receivable, the Company evaluates customers’ financial condition and generally collateral is not required. As of December 31, 2018 and 2017, there were no customers that represented more than 10% of the Company’s net trade accounts receivable or more than 10% of the Company’s revenue in any of the periods presented. Property and Equipment Property and equipment are stated at cost less accumulated depreciation. Depreciation on property and equipment is computed on the straight-line method over the estimated useful life of the asset or the lease term (for leasehold improvements), whichever is shorter. Upon retirement or sale, the cost of the disposed asset and the related accumulated depreciation are removed and any resulting gain or loss is recorded in the consolidated statements of operations. Maintenance and repairs that do not improve or extend the lives of the respective assets are charged to expense in the period incurred. Research and Development Research and development expenses consist primarily of personnel and related expenses for the Company’s research and development staff, including salaries, benefits, bonuses and stock-based compensation, and allocated overhead. Expenditures for research and development are expensed as incurred. Software Capitalization Software development costs for hosting customer transactions (i.e., cloud-based software solutions) are capitalized once the project is in the application development stage in accordance with the accounting guidance for internal-use software. These capitalized costs include external direct costs of services consumed in developing or obtaining the software and personnel expenses for employees who are directly associated with the development. Capitalization of these costs concludes once the project is substantially complete and the software is ready for its intended purpose. Post-configuration training and maintenance costs are expensed as incurred. For the years ended December 31, 2018, 2017, and 2016, $1.1 million, $1.0 million, and $0.8 million software development costs were capitalized, respectively. Capitalized software development costs are amortized on a straight-line basis over the estimated useful life, generally 6 years. In circumstances where software is developed for both cloud-based software solutions and for the purpose of being sold, leased or otherwise marketed (i.e., customer hosted software), capitalization of development costs occurs after technological feasibility of the software is established and continues until the product is available for general release to customers. Since the Company’s developed software is available for general release concurrent with the establishment of technological feasibility, development costs are not capitalized in these circumstances. Acquisitions and Goodwill The Company’s identifiable assets acquired and liabilities assumed in a business combination are recorded at their acquisition date fair values. The valuation requires management to make significant estimates and assumptions, especially with respect to long-lived and intangible assets. Critical estimates in valuing intangible assets include, but are not limited to: • future expected cash flows from customer agreements, customer lists, distribution agreements, and proprietary technology and non-compete agreements; • assumptions about the length of time the brand will continue to be used in the Company’s suite of solutions; and • discount rates used to determine the present value of recognized assets and liabilities. The Company’s estimates of fair value are based upon assumptions it believes to be reasonable, but that are inherently uncertain and unpredictable. Assumptions may be incomplete or inaccurate, and unanticipated events and circumstances may occur. Goodwill is calculated as the excess of the purchase price over the fair value of net assets, including the amount assigned to identifiable intangible assets. Acquisition-related costs, including advisory, legal, accounting, valuation, and other costs, are expensed in the periods in which these costs are incurred. The results of operations of an acquired business are included in the consolidated financial statements beginning at the acquisition date. Goodwill is tested for impairment annually on October 31, or in the event of certain occurrences. Goodwill impairments of $9.2 million and $8.4 million were recorded for the years ended December 31, 2018 and 2017, respectively (See Note 6). There was no goodwill impairment recorded for the year ended December 31, 2016. The Company estimates the fair value of the acquisition-related earnout using various valuation approaches, as well as significant unobservable inputs, reflecting the Company’s assessment of the assumptions market participants would use to value these liabilities. The fair value of the earnout is remeasured each reporting period, with any change in the value recorded as other income or expense. The Company recorded income of $0.4 million and $0.7 million, and expense of $0.3 million for the years ended December 31, 2018, 2017, and 2016, respectively. Long-Lived Assets The Company evaluates long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of these assets may not be recoverable. An impairment is recognized in the event the carrying value of such assets exceeds their fair value. If the carrying value exceeds the fair value, then an impairment test is performed to determine the fair value. In 2018, the Company evaluated the long-lived intangible assets in the Company’s Brazilian reporting unit for impairment as a result of an interim triggering event discussed in Note 6. No impairment of long-lived assets (other than goodwill as discussed in Note 6), including those in the Brazilian reporting unit, occurred in 2018. See Restructuring Charges for impairment recorded in 2017. No impairment of long-lived assets occurred in 2016. Acquired Intangible Assets Acquired intangible assets consist of developed technology, customer relationships, noncompetition agreements, and tradenames and trademarks, resulting from the Company’s acquisitions. Acquired intangible assets are recorded at fair value on the date of acquisition and amortized over their estimated useful lives on a straight-line basis. Acquisition-related costs, primarily legal fees, are capitalized and included in the cost basis of the intangible asset when incurred. The Company recognizes an earnout liability for acquisitions of intangible assets that are accounted for as an asset acquisition when the liability is earned and the amount is known. The earnout liability is capitalized as part of the cost of the assets acquired and amortized over the remaining useful life of the asset. Income Taxes The Company’s deferred tax assets are determined based on temporary differences between the financial reporting and income tax basis of assets and liabilities and are measured using the tax rates that will be in effect when the differences are expected to reverse. A valuation allowance is recorded when it is more likely than not that some of the deferred tax assets will not be realized. The Company assesses its income tax positions and records tax benefits based upon management’s evaluation of the facts, circumstances, and information available at the reporting date. The objectives of accounting for income taxes are to recognize the amount of taxes payable or refundable for the current year and deferred tax liabilities and assets for the future tax consequences of events that have been recognized in an entity’s financial statements or tax returns. The Company will 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 the financial statements from such a position are measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. Judgment is required in assessing the future tax consequences of events that have been recognized in the Company’s consolidated financial statements or tax returns. Variations in the actual outcome of these future tax consequences could materially impact the consolidated financial statements. The Company accounted for the tax effects of The Tax Cuts and Jobs Act (the “Tax Act”), enacted on December 22, 2017, on a provisional basis as of December 31, 2017. The Company completed its accounting during the one-year measurement period from enactment ending December 31, 2018. See Note 11 for further discussion of impacts of the Tax Act. Revenue Recognition The Company primarily generates revenue from fees paid for subscriptions to tax compliance solutions and fees paid for services performed in preparing and filing tax returns on behalf of its customers. Amounts that have been invoiced are recorded in accounts receivable and deferred revenue or revenue, depending upon whether the revenue recognition criteria have been met. In most instances, the initial arrangement with customers includes multiple elements, comprised of subscription and/or professional services, along with non-refundable upfront fees for new customers. The Company evaluates each element in a multiple-element arrangement to determine whether it represents a separate unit of accounting. An element constitutes a separate unit of accounting when the delivered item has standalone value and delivery of the undelivered element is probable and within the Company’s control. Other than nonrefundable upfront fees, the Company’s services typically have standalone value because they are routinely sold separately. Professional services also have standalone value because there are third party vendors that provide similar professional services to customers on a standalone basis. If one or more of the deliverables does not have standalone value upon delivery, the deliverables that do not have standalone value are generally combined with the final deliverable within the arrangement and treated as a single unit of accounting. Revenue for arrangements treated as a single unit of accounting is generally recognized over the period beginning upon delivery of the final deliverable and continuing over the remaining term of the subscription contract. The Company allocates revenue to each element in an arrangement based on the selling price hierarchy. The selling price for a deliverable is based on its vendor-specific objective evidence (“VSOE”), if available, third-party evidence (“TPE”), or best estimate of selling price (“BESP”), if neither VSOE nor TPE is available. As the Company has been unable to establish VSOE or TPE for the elements of its arrangements, the Company establishes the BESP for each element. The determination of BESP requires significant estimates and judgments. BESP is determined by considering the Company’s overall pricing objectives and current market conditions. Other factors considered include existing pricing and discounting practices, historical comparisons of contract prices to list prices, customer demographics, and gross margin objectives. Revenue recognition begins when all the following criteria are met: • There is persuasive evidence of an arrangement; • The product or service is delivered to the customer; • The amount of fees to be paid by the customer is fixed or determinable; and • The collection of the fees is reasonably assured. Sales and other taxes collected from customers to be remitted to the taxing jurisdiction are excluded from revenues. Subscription and Returns Revenue Subscription and returns revenue primarily consists of contractually agreed upon fees paid for using the Company’s cloud-based solutions and fees paid for preparing and filing transaction tax returns on behalf of customers. Under the Company’s subscription agreements, customers select a price plan that includes an allotted number of maximum transactions over the subscription term. Unused transactions are not carried over to the customer’s next subscription term, and customers are not entitled to refund of fees paid or relief from fees due in the event they do not use the allotted number of transactions. If customers exceed the maximum transaction level within their price plan, the Company will generally upgrade the customer to a higher transaction price plan or, in some cases, charge overage fees on a per transaction basis. The Company’s subscription arrangements do not provide the customer with the right to take possession of the software supporting the cloud-based application services. The Company’s subscription contracts are generally non-cancelable except where contract terms provide rights to cancel in the first 60 days of the contract term. The Company reserves for estimated cancellations based on actual history. Current history of customer cancellations has not had a significant impact on revenue recognized. The Company invoices its subscription customers for the initial term at contract signing and at each subscription renewal. Initial terms generally range from twelve to eighteen months, and renewal periods are typically one year. Amounts that are contractually billable and have been invoiced, or which have been collected as cash are initially recorded as deferred revenue. While most of the Company’s customers are invoiced once at the beginning of the term, a portion of customers are invoiced quarterly or monthly. Tax returns processing services include collection of tax data and amounts, preparation of all compliance forms, and submission to taxing authorities. Returns processing services are charged on a subscription basis for an allotted number of returns to process within a given time period or per return filing. The consideration allocated to a returns subscription is recognized as revenue over the contract period commencing when the subscription services are made available to the customer. The Company recognizes revenue when the return is filed when sold on a per return filing basis. Included in the total subscription fee for cloud-based solutions are non-refundable upfront fees that are typically charged to each of the Company’s new customers. These fees are associated with work performed to set up a customer with the Company’s services, and do not have standalone value. The Company recognizes revenue for these fees over the expected term of the customer relationship, beginning when services commence. As of January 1, 2016, and through December 31, 2018, the Company estimated an expected customer relationships term of 6 years. The Company continues to evaluate the expected customer life and it is possible that the expected term of customer relationships may change in future periods. Included in subscription and returns revenue is interest income on funds held for customers. The Company uses trust accounts at FDIC-insured institutions to provide tax remittance services to customers and collect funds from customers in advance of remittance to tax authorities. Prior to remittance, the Company earns interest on these funds. The interest income earned on funds held for customers was $1.1 million for the year ended December 31, 2018. Prior to April 1, 2018, the Company did not earn interest on these funds. Professional Services Revenue The Company bills for service arrangements on a fixed fee or time and materials basis. Professional services revenue includes fees from providing tax analysis, configurations, data migrations, integration, training, and other support services. The consideration allocated to professional services is recognized as revenue when services are performed and are collectable under the terms of the associated contracts. Deferred Revenue Deferred revenue consists of customer billings and payments in advance of revenue being recognized from the Company’s contracts. The Company typically invoices its customers annually in advance for its subscription-based contracts. Deferred revenue and accounts receivable are recorded at the beginning of the new subscription term. For some customers, the Company invoices in monthly, quarterly, or multi-year installments and, therefore, the deferred revenue balance does not necessarily represent the total contract value of all non-cancelable subscription agreements. Deferred revenue anticipated to be recognized during the succeeding 12-month period is recorded as current deferred revenue and the remaining portion is recorded as noncurrent deferred revenue. Integration and Referral Partner Commissions The Company utilizes independent partners to build and maintain integrations for business applications, such as accounting, ERP, ecommerce, POS, recurring billing, and CRM systems. These integrations link the business application to the Company’s cloud-based software solutions. Integration partners are paid a commission based on a percentage of the sales that use the integration. In general, integration partners are paid a higher commission for the initial sale to a new customer and a lower commission for renewal sales. Referral partners bring new customers to the Company and receive a commission that is based on a percentage of the first-year sales. Some of the Company’s integration partners also refer customers that have purchased the partner’s business application. The Company recognizes commissions related to integration and referral partners in sales and marketing costs when a binding customer order is agreed to by the Company and the customer. The Company expenses partner commissions as incurred and classifies these costs as sales and marketing expenses. Partner commissions totaled $21.7 million, $14.3 million, and $9.9 million for the years ended December 31, 2018, 2017, and 2016, respectively. An immaterial portion of the Company’s revenue is generated from sales made through integration partners, rather than through the Company. For these transactions, the Company evaluates whether revenue should be presented on a gross basis, which is the amount that a customer pays for the Company’s solution, or on a net basis, which is the customer payment less partner commissions. The Company has determined that a gross presentation is appropriate for revenue generated through these integration partners, because the Company is the primary provider of services to the end customers and is the primary obligor in these relationships. In addition, the Company has customer credit risk for non-payment, and the Company has latitude in establishing and negotiating prices on transactions from these sources. Cost of Revenue Cost of revenue consists of personnel and related expenses for providing the Company’s solutions and supporting its customers, including salaries, benefits, bonuses, and stock-based compensation, direct costs and allocated costs associated with information technology, tax content, and allocated rent and overhead. Advertising Costs The Company expenses all advertising costs as incurred and classifies these costs as sales and marketing expenses. Advertising expenses were $18.8 million, $22.7 million, $19.6 million for the years ended December 31, 2018, 2017, and 2016, respectively. Leases The Company is a lessee of facilities in the United States, Canada, United Kingdom, Belgium, Brazil, and India and certain other equipment under non-cancelable lease agreements. The Company categorizes leases at their inception as either operating or capital leases. For certain lease agreements, the Company may receive rent holidays and other incentives, including allowances for leasehold improvements. Future operating lease payments are recognized as rent expense on a straight-line basis without regard to deferred payment terms, such as rent holidays. Incentives received are treated as a reduction of rent expense over the term of the agreement. Leasehold improvements are capitalized at cost and amortized over the lesser of their estimated useful life or the term of the lease. Foreign Currency Translation Assets and liabilities of each of the Company’s foreign subsidiaries are translated at the exchange rate in effect at each period-end. Consolidated statement of operations amounts are translated at the average rate of exchange prevailing during the period. Translation adjustments arising from differing exchange rates from period to period are included in accumulated other comprehensive income (loss) within shareholders’ equity (deficit). Employee Benefit Plan The Company offers a salary deferral 401(k) plan for its U.S. employees. The plan allows employees to contribute a percentage of their pretax earnings annually, subject to limitations imposed by the Internal Revenue Service. The plan also allows the Company to make a matching contribution, subject to certain limitations. The Company contributed $0.8 million, $0.7 million, and $0.6 million to the plan in 2018, 2017, and 2016, respectively. Stock-Based Compensation The Company accounts for stock-based compensation by calculating the fair value of each stock option, common stock warrant, restricted stock unit (“RSU”), or purchase right issued under the Company’s 2018 Employee Stock Purchase Plan (“ESPP”) at the date of grant. The fair value of stock options, common stock warrants, and purchase rights issued under the ESPP is estimated by applying the Black-Scholes option-pricing model. This model uses the fair value of the Company’s underlying common stock at the measurement date, the expected or contractual term of the option, the expected volatility of its common stock, risk-free interest rates, and expected dividend yield of its common stock. The fair value of an RSU is determined using the fair value of the Company’s underlying common stock on the date of grant. Beginning January 1, 2017, the Company accounts for forfeitures as they occur. Deferred Financi

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements Assets and liabilities measured at fair value on a recurring basis The fair value measurements of assets and liabilities recognized in the accompanying consolidated balance sheets measured at fair value on a recurring basis and the level within the fair value hierarchy in which the fair value measurements fall on dates presented as follows (in thousands): Fair Value Measurements Using Quoted Prices Significant in Active Other Significant Markets for Observable Unobservable Fair Identical Assets Inputs Inputs December 31, 2018 Value (Level 1) (Level 2) (Level 3) Money market funds $ 138,483 $ 138,483 Earnout related to acquisitions — Fair Value Measurements Using Quoted Prices Significant in Active Other Significant Markets for Observable Unobservable Fair Identical Assets Inputs Inputs December 31, 2017 Value (Level 1) (Level 2) (Level 3) Money market funds $ 10,261 $ 10,261 $ $ Earnout related to acquisitions 380 380 The Company uses the fair value hierarchy for financial assets and liabilities. The Company’s non-financial assets and liabilities, which include goodwill, intangible assets, and long-lived assets, are not required to be measured at fair value on a recurring basis. Earnout Liability The Company estimates the fair value of earnout liabilities using the probability-weighted discounted cash flow and Monte Carlo simulations. The Company measured the fair value of the VAT Applications earnout liability upon acquisition of the company in 2015 using a Monte Carlo simulation approach which utilized a discount rate of 15% and a risk-free rate based on linear interpolated U.S. Treasury rates commensurate with the term. As of December 31, 2016, the earnout liability was valued utilizing a discount rate of 16% and a risk-free rate based on linear interpolated U.S. Treasury rates commensurate with the term. During 2017, the Company agreed to settle its earnout obligations under the VAT Applications acquisition agreement for €2.5 million, or approximately $3.1 million. This fixed amount was paid in 2018. In 2016, the Company acquired Gyori Eto Empreendimentos e Particpacoes (“Gyori”), a business that provides certain tax-related compliance solutions and content for the Brazilian market (see Note 5). The Company measured the fair value of the acquisition earnout liability using a Monte Carlo simulation approach which utilized a discount rate of 19% and a risk-free rate based on linear interpolated U.S. Treasury rates commensurate with the term. As of December 31, 2016 and 2017, the earnout liability was valued utilizing a discount rate of 20% and 22% respectively, and a risk-free rate based on linear interpolated U.S. Treasury rates commensurate with the term. As of December 31, 2018, the fair value of the earnout liability was determined to be zero. Earnout liabilities are classified as Level 3 liabilities because the Company uses unobservable inputs to value them, reflecting its assessment of the assumptions market participants would use to value these liabilities. Changes in the fair value of earnout liability are recorded as other (income) expense, net in the consolidated statements of operations. A reconciliation of the beginning and ending balances of recurring fair value measurements recognized in the accompanying consolidated balance sheets using significant unobservable (Level 3) inputs, except of the earnout liability for VAT Applications, is as follows (in thousands): December 31, December 31, 2018 2017 Earnout liability: Balance beginning of period $ 380 $ 6,235 Payments of earnout liability — (2,101 ) Settlement of earnout liability — (3,051 ) Total unrealized (gains) losses included in other income (380 ) (703 ) Balance end of period $ — $ 380 Assets measured at fair value on a non-recurring basis During 2018 and 2017, certain non-financial assets were measured at fair value on a non-recurring basis, including goodwill and certain intangible assets. In 2018, goodwill related to the Brazilian reporting unit, with a total carrying value of $9.2 million after considering currency fluctuations during the year, was written down to fair value of zero, resulting in a $9.2 million impairment charge in the year ended December 31, 2018. In 2017, goodwill related to the Brazilian reporting unit, with a total carrying value of $19.8 million was written down to fair value of $11.4 million, resulting in an impairment charge of $8.4 million in the year ended December 31, 2017. The fair value was determined using significant unobservable (Level 3) inputs. See Note 6 for additional details on the impairment charge and valuation methodologies.

Balance Sheet Detail

Balance Sheet Detail	12 Months Ended
	Dec. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Detail	4. Balance Sheet Detail Property and equipment, net consisted of the following (in thousands): Useful December 31, December 31, Life (Years) 2018 2017 Computer equipment and software 3 $ 12,904 $ 12,884 Internally developed software 6 3,620 2,512 Furniture and fixtures 5 5,850 4,459 Office equipment 5 586 622 Leasehold improvements 1 to 10 26,788 20,339 49,748 40,816 Accumulated depreciation (16,375 ) (15,422 ) Property and equipment—net $ 33,373 $ 25,394 Depreciation expense was $6.8 million, $4.9 million, and $5.2 million, for the years ended December 31, 2018, 2017, and 2016, respectively. Prepaid expenses and other current assets (in thousands): December 31, December 31, 2018 2017 Prepaid expenses $ 9,578 $ 5,077 Deferred financing costs 643 1,575 Deposits 325 244 Other 761 120 Total $ 11,307 $ 7,016 Accrued expenses and trade payables consisted of the following (in thousands): December 31, December 31, 2018 2017 Accrued payroll and related taxes $ 3,800 $ 4,155 Accrued bonus 10,766 6,280 Accrued sales commissions 6,889 2,904 ESPP contributions 6,473 - Accrued state, federal, and local taxes 1,827 1,044 Accrued referral source commissions 5,535 4,270 Trade payables 4,847 9,822 Earnout liabilities 116 3,061 Accrued leasehold improvements 424 1,288 Other 6,387 5,340 Total $ 47,064 $ 38,164

Acquisition

Acquisition	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Acquisition	5. Acquisition September 2016 Acquisition of Gyori in Brazil On September 22, 2016, the Company completed a stock purchase agreement (the “Gyori Purchase”) to acquire Gyori Eto Empreendimentos e Particpacoes (“Gyori”), a business that provides tax-related compliance solutions and content for the Brazilian market. The business was previously conducted by five separate companies and was combined into one holding company, Gyori, several months prior to the closing of the acquisition. The Company accounted for the Gyori Purchase as a business combination. As a result of the acquisition, the Company further expanded its global reach and its ability to provide transaction tax solutions in one of the world’s most complicated transaction tax jurisdictions. The Company continues to integrate Gyori’s operations, including sales activities and general and administrative functions into the Company’s worldwide operations, and has re-branded the product offerings to use the Avalara tradename. Acquisition-related costs of $1.2 million for the year ended December 31, 2016 were primarily for professional fees to perform due diligence and legal fees associated with the acquisition. The total purchase price was $21.7 million, consisting of $17.2 million in cash, 285,710 shares of common stock valued at $3.8 million, and an earnout provision valued upon acquisition at $0.7 million with a maximum payout of $6.8 million based on future financial performance. The earnout provides for three annual payouts based on achieving specified growth in base annual recurring revenue (“BARR”) for each year. The BARR, as defined in the stock purchase agreement, is based on such revenue from July 1, 2015 to June 30, 2016. The maximum annual payments that can be earned in each of the next three-year periods is as follows: (1) For Year 1 (July 1, 2016 to June 30, 2017) achieving 25% growth over BARR earns $0.6 million; (2) for Year 2 (July 1, 2017 to June 30, 2018), achieving 68.75% growth over BARR earns $2.5 million; and (3) for Year 3 (July 1, 2018 to June 30, 2019), achieving 144.69% growth over BARR earns $3.7 million. The earnout was originally recognized at fair value at the date of the business combination and was recorded as a liability on the balance sheet. The earnout is adjusted to fair value quarterly (see Note 3). No amounts were earned in the Year 1 or Year 2 performance periods. The allocation of the fair value of the assets acquired and the liabilities assumed in the Gyori Purchase is provided in the following table (in thousands): Assets acquired: Current assets $ 628 Other non-current assets 65 Developed technology, customer relationships, and other intangibles 4,669 Goodwill (includes assembled workforce) 19,382 Total assets acquired 24,744 Liabilities assumed: Debt obligations, current portion 495 Other current liabilities 903 Debt obligations, non-current portion 89 Deferred tax liabilities 1,257 Other non-current liabilities 349 Total liabilities assumed 3,093 Net assets acquired $ 21,651 The Company utilizes different valuation approaches and methodologies to determine the fair value of the acquired assets. A summary of the valuation methodologies, significant assumptions, and estimated useful lives of acquired intangibles in the Gyori Purchase are provided in the below table (in thousands): Intangible Assigned Value Valuation Methodology Discount Rate Assigned Useful Life Customer relationships $ 1,073 Multi-period excess earnings-income approach 20.0 % 10 years Trademarks and trade names 81 Relief from royalty- income approach 20.0 % 1 year Developed technology and customer database 3,387 Relief from royalty- income approach 19.0 % 6 years Noncompetition agreements 128 With-and-without valuation- income approach 20.0 % 3 years The excess of the purchase price over the net identifiable tangible and intangible assets of $19.4 million was recorded as goodwill, which includes synergies expected from the combined service offerings and the value of the assembled workforce. The goodwill is expected to be non-deductible for tax purposes. During the third quarter of 2018, the Company recorded a $9.2 million goodwill impairment charge related to the Brazil business (see Note 6). During the fourth quarter of 2017, the Company recorded an $8.4 million goodwill impairment charge related to the Brazil business. The charge is included in Goodwill impairment in the consolidated statement of operations. For the period from the date of the Gyori acquisition through December 31, 2016, revenue was $1.2 million and the pre-tax loss was $1.4 million from the Gyori business. The unaudited pro forma combined results of operations for the year ended December 31, 2016 for Avalara and Gyori as though the companies were combined as of January 1, 2016 is revenue of $172.0 million and net loss of $59.7 million. The unaudited pro forma financial information also included the business combination accounting effects resulting from the acquisition, including amortization charges from acquired intangibles. The unaudited pro forma financial information is for informational purposes only and is not necessarily indicative of the results of operations that would have been achieved if the Gyori acquisition had taken place as of January 1, 2016.

Intangible Assets

Intangible Assets	12 Months Ended
	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible Assets	6. Intangible Assets Finite-lived intangible assets consisted of the following (in thousands): December 31, 2018 Average Useful Life (Years) Gross Accumulated Amortization Net Customer relationships 3 to 10 $ 15,412 $ (9,202 ) $ 6,210 Developed technology 3 to 8 30,935 (17,806 ) 13,129 Noncompete agreements 3 to 5 574 (542 ) 32 Tradename and trademarks 1 to 4 420 (420 ) — $ 47,341 $ (27,970 ) $ 19,371 December 31, 2017 Average Useful Life (Years) Gross Accumulated Amortization Net Customer relationships 3 to 10 $ 15,270 $ (7,347 ) $ 7,923 Developed technology 3 to 8 24,781 (13,785 ) 10,996 Noncompete agreements 3 to 5 586 (446 ) 140 Tradename and trademarks 1 to 4 419 (404 ) 15 $ 41,056 $ (21,982 ) $ 19,074 Finite-lived intangible assets are generally amortized on a straight-line basis over the remaining estimated useful life as management believes that this reflects the expected benefit to be received from these assets. Finite-lived intangible assets amortization expense was $6.0 million, $5.7 million, and $5.1 million, for the years ended December 31, 2018, 2017, and 2016, respectively. Future amortization expense as of December 31, 2018, related to these finite-lived intangible assets is expected to be as follows (in thousands): Years Ending December 31 2019 $ 5,652 2020 4,607 2021 3,355 2022 2,413 2023 1,989 Thereafter 1,355 $ 19,371 Acquisitions of finite-lived intangible assets In May 2018, the Company acquired certain intangible assets from Atlantax Systems, Inc (“Atlantax”) pursuant to a purchase arrangement structured to incent Atlantax to convert their existing customers to become Avalara customers. Total consideration for the purchase is based on an earnout computed on future revenue recognized by the Company over the next four years, up to a maximum of $1.9 million. At closing, the Company funded $0.4 million to Atlantax as a prepayment against future earnings. As of December 31, 2018, the total prepayment of $0.4 million was capitalized as a customer relationship intangible asset and is being amortized using an estimated useful life of five years. As future earnout payments become known, those costs will be capitalized as part of the customer relationship asset and amortized over the remaining useful life. The Company incurred immaterial legal costs related to the transaction that were capitalized as part of the customer relationship asset. In May 2018, the Company acquired developed technology to facilitate cross-border transactions (e.g., tariffs and duties), from Tradestream Technologies Inc. and Wise 24 Inc. (the “Sellers”) for cash and common stock. Total consideration for the purchase includes an earnout computed on future revenue and billings recognized by the Company over the next six years, up to a maximum of $30.0 million. The earnout is payable in cash and common stock at the end of each six-month measurement period ending on June 30 or December 31 through 2023, with the first earnout period ending December 31, 2018. The cash portion of the earnout is computed based on eligible billings in the measurement period. The number of shares of common stock to be issued is computed based on the eligible revenue recognized in the measurement period divided by the average closing price of the Company’s common stock during the last ten days of the measurement period. At closing, the Company made a $1.5 million cash payment to the Sellers and made an additional $2.5 million cash payment in June 2018. Under the asset purchase agreement, the Company is also required to issue 113,122 shares of common stock as follows: 37,708 shares on November 29, 2018, 37,708 shares on May 29, 2019, and 37,706 shares on November 29, 2019. While the initial cash payments totaling $4.0 million are non-refundable, they are a prepayment against future earnout payments and will reduce the future cash portion of the earnout. The earnout payments, initial cash payments and equity issuances described above are all subject to clawback or set-off, as applicable, in the event of certain claims for which the Company is indemnified by the Sellers and their shareholders. The Company incurred approximately $0.1 million in legal costs related to the transaction that were capitalized as part of the developed technology asset. As of December 31, 2018, total consideration of $7.1 million, consisting of the cash paid, the fair value of the Company’s common stock on the date of the asset purchase, and the transaction costs incurred, was allocated to the acquired assets based on the relative fair value, consisting of a $6.6 million developed technology intangible asset that will be amortized using an estimated useful life of 6 years and a $0.5 million current other receivable for a refundable tax credit owed to the Company related to transfer taxes paid to the Sellers. As future earnout payments become due, those costs will be capitalized as part of the developed technology asset and amortized over the remaining useful life. As of December 31, 2018, an earnout liability of $0.1 million was recorded within accrued expenses and trade payables on the consolidated balance sheet. Goodwill Changes in the carrying amount of goodwill through December 31, 2018, are summarized as follows (in thousands): Balance—January 1, 2018 $ 72,482 Cumulative translation adjustments (2,008 ) Goodwill impairment (9,174 ) Balance—December 31, 2018 $ 61,300 Goodwill is tested for impairment annually on October 31 at the reporting unit level or whenever circumstances occur indicating goodwill might be impaired. The impairment test involves comparing the fair value of each reporting unit to its carrying value, including goodwill. Fair value reflects the price a market participant would be willing to pay in a potential sale of the reporting unit. If the fair value exceeds the carrying value, the Company will conclude that no goodwill impairment has occurred. If the carrying value of the reporting unit exceeds its fair value, the Company will recognize an impairment loss in an amount equal to the excess, not to exceed the carrying value. The Company has three reporting units for goodwill impairment testing consisting of its U.S., European, and Brazilian operations. During the third quarter of 2018, the Company updated its long-term cash flow forecast for the Brazilian reporting unit to reflect recent performance indicators that suggested it will take longer to execute on the Company’s long-term strategies to achieve anticipated growth and cash flow objectives. The updated long-term cash flow forecast indicated a longer time horizon to positive cash flow, compared to the last update in the fourth quarter of 2017. As a result, management concluded that there was an interim triggering event and performed an impairment test during the third quarter of 2018 on an interim basis. This test resulted in a $9.2 million impairment of the Brazilian goodwill reporting unit, which was recorded during the third quarter of 2018. The goodwill impairment charge is included in Goodwill impairment in the consolidated statements of operations. The Company used a quantitative approach to measure the fair value of its Brazilian reporting unit using a discounted cash flow approach, which is a Level 3 measurement. The Company concluded it was not appropriate to use a market valuation approach due primarily to a lack of publicly traded companies in similar businesses. The discounted cash flow analysis requires significant judgments, including estimation of future cash flows, which is dependent on internal forecasts, determination of the Company’s weighted average cost of capital, which is risk-adjusted to reflect the specific risk profile of the reporting unit being tested, and determination of revenue multiples, which are based on guideline public company multiples and adjusted for the specific size and risk profile of the reporting unit. The weighted average cost of capital used in the Company’s analysis was 30%. Upon completion of the analysis, the fair value of the Brazilian reporting unit was substantially less than the carrying value. As part of the Company’s annual impairment test, a qualitative impairment test was performed for the Company’s U.S. reporting unit. The Company concluded it is more likely than not that the fair value of the reporting unit exceeds its carrying value. A quantitative impairment test was performed for the Company’s European reporting unit. Upon completion, the fair value of the European reporting unit was in excess of the carrying value. When following a quantitative approach, the Company measures the fair value of its reporting units using a combination of a discounted cash flow approach and the market valuation approach using publicly traded company multiples in similar businesses, which are Level 3 measurements. This analysis requires significant judgments, including estimation of future cash flows, which is dependent on internal forecasts, determination of the Company’s weighted average cost of capital, which is risk-adjusted to reflect the specific risk profile of the reporting unit being tested, and determination of revenue multiples, which are based on guideline public company multiples and adjusted for the specific size and risk profile of the reporting unit. The weighted average cost of capital used in the Company’s most recent annual impairment test was 25%. In the first ten months of 2017, the Brazilian reporting unit did not meet revenue or cash flow objectives due primarily to longer than expected integration efforts and a smaller proportion of recurring revenues than previously anticipated. This led to a delay in the forecasted timing of future revenue and cash flow compared to previous expectations. In addition to delaying cash flows, management also updated its internal forecast to reflect lower assumed future revenue growth rates. As a result, management concluded that an $8.4 million impairment adjustment was required. The goodwill impairment charge is included in Goodwill impairment in the consolidated statements of operations. The Company had $17.6 million and $8.4 million of accumulated goodwill impairment as of December 31, 2018 and 2017, respectively. As of December 31, 2018, the Company has no remaining goodwill associated with the Brazilian reporting unit.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and Contingencies Leases The Company has non-cancelable operating leases for office facilities in the United States, Canada, United Kingdom, Belgium, Brazil and India that expire through 2028. Rent expense was $9.9 million, $5.7 million, and $4.8 million, for the years ended December 31, 2018, 2017, and 2016, respectively. The Company’s obligation for payments under these leases is as follows (in thousands): Years Ending December 31 Operating Leases 2019 $ 9,095 2020 9,533 2021 10,048 2022 9,585 2023 8,965 Thereafter 32,729 Total minimum lease payments ( 1) $ 79,955 (1) In June 2016, the Company entered into an office lease agreement (the “King Street Lease”), which the Company began using in the first quarter of 2018 for its new corporate headquarters. The Company’s lease for its former corporate headquarters will expire at the end of 2022. The Company entered into a sublease agreement for its former corporate headquarters in the fourth quarter of 2018. Sublease income was $0.3 million for 2018. The King Street Lease provides for a term of 120 full calendar months commencing when the Landlord delivers the premises to the Company, which was in the first quarter of 2018. Pursuant to the King Street Lease, base rent will be approximately $231,424 per month for the first ten months following the commencement of the term, and will increase each twelve-month period thereafter and as additional floors are added to the lease. Further, base rent will be approximately $578,872 per month for the final twelve months of the lease. The base rent payments do not include the Company’s proportionate share of any operating expenses for the location. Commitments The Company has commitments related to network infrastructure, hosting services, and software licenses. The Company’s obligation for future payments under these contracts is $4.4 million, $3.5 million, and $3.5 million for each of the years ending December 31, 2019 through 2021, respectively. Contingencies Loss contingencies may arise in connection with the ordinary conduct of the Company’s business activities. The Company considers all loss contingencies on a quarterly basis and based on known facts assesses whether potential losses are considered reasonably possible, probable and estimable. The Company establishes an accrual for loss contingencies when the loss is both probable and reasonably estimable. These accruals represent management’s estimate of probable losses and, in such cases, there may be an exposure to loss in excess of the amounts accrued. Significant judgment is required to determine both likelihood of there being a probable loss and the estimated amount of a loss. If a loss contingency is not both probable and reasonably estimable, the Company does not establish an accrual, but will evaluate other disclosure requirements and continue to monitor the matter for developments that would make the loss contingency both probable and reasonably estimable. The ultimate outcome of any litigation relating to a loss contingency is uncertain and, regardless of outcome, litigation can have an adverse impact on the Company because of defense costs, negative publicity, diversion of management resources and other factors. Pursuant to the Company’s agreement with the Streamlined Sales Tax Governing Board, Inc., or SST, the Company calculates and remits sales taxes to certain states on behalf of its customers, and that agreement contains provisions detailing the circumstances under which the Company may become liable to member states in the event of delinquent payment of taxes. In a situation where the state is conducting a sales tax audit and the Company’s customer has declared bankruptcy or otherwise terminated operations before the appropriate documentation or tax liabilities have been remitted to the taxing jurisdiction, the Company could be held to be financially responsible for certain tax liabilities. The Company accrues for estimated losses for SST sales tax audits at the time it recognizes revenue based on an evaluation of the history of loss in comparison to historical revenue. The Company adjusts this estimate as needed when actual experience differs from previously recorded amounts, or when a particularly significant or unusual claim or liability is deemed probable of payment by the Company. The reserve for estimated losses from SST sales tax audits is $0.1 million and $0.1 million as of December 31, 2018 and 2017, respectively. In its standard subscription agreements, the Company has agreed to indemnification provisions with respect to certain matters. Further, from time to time, the Company has also assumed indemnification obligations through its acquisition activity. These indemnification provisions can create a liability to the Company if its services do not appropriately calculate taxes due to tax jurisdictions, or if the Company is delinquent in the filing of returns on behalf of its customers. Although the Company’s agreements have disclaimers of warranties that limit its liability (beyond the amounts the Company agrees to pay pursuant to its indemnification obligations and guarantees, as applicable), a court could determine that such disclaimers and limitations are unenforceable as a matter of law and hold the Company liable for certain errors. Further, in some instances the Company has negotiated agreements with specific customers or assumed agreements in connection with the Company’s acquisitions that do not limit this liability or disclaim these warranties. It is not possible to reasonably estimate the potential loss under these indemnification arrangements. While the Company has never paid a material claim related to these indemnification provisions, the Company believes that, as of December 31, 2018 and 2017, there is a reasonable possibility that a loss may be incurred pursuant to certain of these arrangements and estimates a range of loss of up to $2.0 million. The Company has not recorded an accrual related to these arrangements as of December 31, 2018 or 2017 because it has not determined that a loss is probable. While no claim has been asserted against the Company, if such claim were made, the Company would vigorously defend itself. The ultimate outcome of these potential obligations is unknown, and it is possible that the actual losses could be higher than the estimated range. On October 22, 2018, PTP OneClick, LLC (“PTP”) filed a lawsuit against Avalara, Inc. in the United States District Court for the Eastern District of Wisconsin. The lawsuit alleges that making, using, offering to sell, and selling AvaTax, Avalara Returns, and TrustFile (the “Avalara Products”) infringe U.S. Patent No. 9,760,915 held by PTP and also alleges unspecified trade secret misappropriation, unfair competition, and breach of contract. PTP seeks judgments of willful patent infringement, willful trade secret misappropriation, unfair competition, and breach of contract. PTP requests preliminary and permanent injunctions to enjoin the Company from making, using, offering to sell, and selling the Avalara Products along with treble damages and attorneys’ fees. Based upon the Company’s review of the complaint and the specified patent, the Company believes that the Company has meritorious defenses to PTP’s claims. On November 7, 2018, the Company moved to dismiss the lawsuit and to have the patent held invalid. The Company has also moved to transfer the matter to the United States District Court located in Seattle, Washington. The Company intends to continue to vigorously defend against PTP’s allegations.

Debt

Debt	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Debt	8. Debt Loan and Security Agreement In November 2017, the Company amended its June 2016 loan and security agreement with Silicon Valley Bank and Ally Bank (the “Lenders”). The credit arrangements included a senior secured $30.0 million term loan facility that was repaid in August 2018, and currently includes a $50.0 million revolving credit facility (collectively, the “Credit Facilities”). The $50.0 million revolving credit facility, which is subject to a borrowing base limitation and is reduced by outstanding letters of credit, must be repaid in November 2019. The obligations under the Credit Facilities are collateralized by substantially all the assets of the Company, including intellectual property, receivables, and other tangible and intangible assets. Using a portion of the proceeds from the IPO, in June 2018, the company repaid $33.0 million of borrowings outstanding under the revolving credit facility and in August 2018, the Company repaid $30.0 million of borrowings outstanding under the term loan. There were no borrowings outstanding under the Credit Facilities as of December 31, 2018. Collectively, the Credit Facilities include several affirmative and negative covenants, including a requirement that the Company maintain minimum net billings and minimum liquidity and observe restrictions on dispositions of property, changes in its business, mergers or acquisitions, incurring indebtedness, and distributions or investments. Written consent of the Lenders is required to pay dividends to shareholders, with the exception of dividends payable in common stock. As of December 31, 2018, the Company was in compliance with all covenants of the Credit Facilities. The Company is required to pay a quarterly fee of 0.50% per annum on the undrawn portion available under the revolving credit facility plus the sum of outstanding letters of credit. Under the Credit Facilities, the interest rate on the revolving credit facility is based on the greater of either 4.25% or the current prime rate plus 1.75%. In August 2008, the Company entered into a note payable for $0.4 million that bears interest at 2.54%. The note was payable and due upon demand with a remaining balance of $0.2 million as of December 31, 2017. The note was repaid in April 2018. Outstanding borrowings consisted of the following (in thousands): December 31, December 31, 2018 2017 Current portion: Credit facilities $ — $ 625 Note payable — 234 Total current portion of long-term debt $ — $ 859 Noncurrent portion: Credit facilities — 38,840 Total noncurrent portion of long-term debt $ — $ 38,840 Deferred financing fees, net of amortization, related to the Credit Facility are reflected as a direct reduction in the carrying amount of noncurrent debt in the balance sheet as of December 31, 2017 and the table above. Upon closing the November 2017 amendment to the Credit Facilities, the Company paid commitment fees to the Lenders of $0.4 million. In the third quarter of 2018, concurrent with the repayment of the remaining borrowings under the Credit Facilities, $0.1 million of the deferred financing fees, net of amortization, related to the term loan were written off. As of December 31, 2018 and 2017, deferred financing fees, net of amortization, were $0.2 million and $0.5 million, respectively. The remaining deferred financing fees as of December 31, 2018 relate to the revolving credit facility and were reclassified to the prepaid expenses and other current assets line item in the balance sheet.

Convertible Preferred Stock and

Convertible Preferred Stock and Shareholders' Equity (Deficit)	12 Months Ended
	Dec. 31, 2018
Stockholders Equity Note [Abstract]
Convertible Preferred Stock and Shareholders' Equity (Deficit)	9. Convertible Preferred Stock and Shareholders’ Equity (Deficit) Authorized Capital—Common Stock and Preferred Stock The Company is authorized to issue two classes of stock designated as common stock and preferred stock. In June 2018, immediately following the IPO, the Board of Directors approved the Amended and Restated Articles of Incorporation, which increased authorized capital stock from 260,290,986 shares, consisting of 153,944,895 shares of common stock, $0.0001 par value per share, and 106,346,091 shares of convertible preferred stock, $0.0001 par value per share, to authorized capital stock of 620,000,000 shares, consisting of 600,000,000 shares of common stock, $0.0001 par value per share, and 20,000,000 shares of undesignated preferred stock, $0.0001 par value per share. There were no changes to the rights and preferences of the common stock as a result of the IPO. During 2018, the Company repurchased shares from employees and non-employee investors at fair value for $1.7 million. Convertible Preferred Stock Immediately prior to the completion of the IPO, all outstanding shares of preferred stock converted into 50,888,014 shares of the Company’s common stock on a 2-to-1 basis. As of December 31, 2018, there were no shares of convertible preferred stock issued and outstanding. The following shares of common stock had been reserved for issuance upon conversion of the preferred stock, (in thousands): December 31, 2017 Conversion of outstanding Series A preferred stock 6,154 Conversion of outstanding Series A-1 preferred stock 2,344 Conversion of outstanding Series A-2 preferred stock 139 Conversion of outstanding Series B preferred stock 896 Conversion of outstanding Series B-1 preferred stock 10,759 Conversion of outstanding Series C preferred stock 3,534 Conversion of outstanding Series C-1 preferred stock 4,255 Conversion of outstanding Series D preferred stock 4,283 Conversion of outstanding Series D-1 preferred stock 11,404 Conversion of outstanding Series D-2 preferred stock 7,122 Total shares of common stock reserved for future issuance 50,890 The Company had designated ten outstanding series of convertible redeemable preferred stock (collectively, the “Series Preferred Stock”, consisting of Series A, A-1, and A-2, Series B and B-1, Series C and C-1, Series D, D-1 and D-2) as of December 31, 2017. As of December 31, 2017, the Company was authorized to issue 106,346,091 shares of preferred stock with a par value of $0.0001 per share. Prior to the IPO, the Series Preferred Stock had conversion to common and liquidation values per share as follows: Preferred Stock Series Purchase Date Conversion Ratio to Common Stock Per Share Liquidation Preference A November 30, 2005 2:1 $ 0.8880 A-1 March 15, 2009 2:1 0.4440 A-2 January 21, 2010 2:1 1.6908 B May 14, 2010 2:1 0.9400 B-1 November 5, 2010 2:1 1.1000 C June 18, 2012 2:1 2.8291 C-1 November 13, 2013 2:1 1.5000 D February 12, 2014 2:1 5.2500 D-1 November 10, 2014 2:1 6.3200 D-2 September 12, 2016 2:1 6.7500 The rights, preferences, privileges, and restrictions for the Series Preferred Stock were as follows: Voting The Series Preferred Stock was entitled to vote on all matters submitted to the shareholders for a vote together with the holders of common stock, in addition to being entitled to vote as a separate class, or classes, on certain other matters. Each share of common stock was entitled to one vote. Each share of Series Preferred Stock was entitled to a number of votes equal to the number of shares of common stock issuable upon conversion of such Series Preferred Stock as of the record date for such vote. Dividends The Company could not declare or pay or set apart any dividend on any shares of Series Preferred Stock unless the Company simultaneously declared and paid an equivalent dividend in respect of each of the other outstanding shares of Series Preferred Stock (on a converted to common basis). No dividends were declared or paid during the years ended December 31, 2018, 2017, and 2016. Liquidation In the event of any voluntary or involuntary liquidation, dissolution, or winding up of the Company, the holders of shares of Series Preferred Stock then outstanding were entitled to receive by reason of their ownership in preference to any distribution of assets of the Company to the holders of the common stock or any other of the preferred stock that ranked junior in liquidation to the Series Preferred Stock, on a pari passu basis, an amount per share equal to the liquidation value plus all declared and unpaid dividends on such shares of Series Preferred Stock. The table above lists the liquidation value of the Series Preferred Stock before adjustment for stock dividends, stock splits, combinations, reorganizations, recapitalizations, reclassifications, or similar transactions affecting the number of outstanding shares. The Series Preferred Stock contained provisions that, in the event of a change in the control of the Company, gave the holders of the Series Preferred Stock liquidation rights equal to the liquidation preference on the Series Preferred Stock. Due to these redemption characteristics, the Company’s convertible preferred stock was presented separate and apart from permanent shareholders’ equity (deficit) in the consolidated balance sheets. Conversion Rights The Series Preferred Stock was convertible to common stock. Any shares of Series Preferred Stock may, at the option of the holder, have been converted at any time into fully-paid and non-assessable shares of common stock. The Series Preferred Stock also contained an anti-dilution conversion feature under which the respective conversion prices established at the time of each issuance of Series Preferred Stock were reset to a lower conversion price, if and when, the Company is to issue additional shares of any class of stock at a price that is lower than the initial conversion price established in each respective issuance of Series Preferred Stock. This form of anti-dilution protection commonly referred to as “down-round protection”, was never triggered. Warrant Instruments There were no warrants to purchase common stock outstanding as of December 31, 2018. At December 31, 2017, the following warrants to purchase common stock were outstanding: Class Shares (In thousands) Exercise Price Fair Value at Issuance Term (Years) Common stock 490 $1.50 to $13.84 $0.178 to $6.280 10 At December 31, 2016, the following warrants to purchase common stock were outstanding: Class Shares (In Exercise Price Fair Value at Issuance Term (Years) Common stock 678 $0.96 to $12.60 $0.046 to $5.120 10 Common Stock Warrants Common stock warrants were granted to the Company’s Board of Directors for services provided. During each of 2018, 2017, and 2016, the Company issued 80,000 common stock warrants with weighted average exercise prices of $16.60, $13.84, and $12.60 per share, respectively. The warrants were valued with a grant date fair value of $0.5 million, $0.5 million, and $0.4 million, respectively, and were expensed as general and administrative expenses for the years ended December 31, 2018, 2017, and 2016, respectively. The common stock warrants contained net settlement provisions that allowed for net exercise and expired in connection with the closing of a public offering of the Company’s common stock, if unexercised at that date. During 2018, and prior to the completion of the IPO, 363,000 common stock warrants were exercised for total proceeds of $3.7 million. Immediately prior to the completion of the IPO, the remaining common stock warrants then outstanding were automatically net exercised into 144,945 shares of the Company’s common stock. See Note 10 for further discussion of how the Company accounts for stock-based compensation.

Equity Incentive Plans

Equity Incentive Plans	12 Months Ended
	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity Incentive Plans	10. Equity Incentive Plans The Company has stock-based compensation plans that provide for the award of equity incentives, including stock options, stock awards, and RSUs. As of December 31, 2018, the Company had stock options outstanding under the 2018 Equity Incentive Plan (the “2018 Plan”), the 2006 Equity Incentive Plan (the “2006 Plan”) and the Taxcient, Inc. (“Taxcient”) 2005 Stock Option Plan (the “Taxcient Plan”) and had RSUs outstanding under the 2018 Plan. As of December 31, 2018, the Company also has an employee stock purchase plan. As of December 31, 2017, the Company had stock options outstanding under In April 2018, the Company’s Board of Directors adopted the 2018 Plan which became effective in connection with the Company’s IPO. The 2018 Plan allows the Company to grant equity incentives to employees, directors, advisors, and consultants providing services to the Company. The 2018 Plan is administered by the Company’s Board of Directors and the Compensation and Leadership Development Committee of the Board of Directors. The total number of shares of common stock reserved for issuance under the 2018 Plan is equal to (1) 5,315,780 shares plus (2) any shares subject to outstanding awards under the 2006 Plan as of June 14, 2018 that subsequently cease to be subject to such awards. The available shares automatically increase each January 1, beginning January 1, 2019, by the lesser of (i) 5% of the aggregate number of shares of common stock outstanding on December 31st of the immediately preceding calendar year (rounded up to the nearest whole share) and (ii) an amount determined by the Company’s Board of Directors. As of December 31, 2018, 265,024 Prior to the 2018 Plan, the Company awarded stock options under the 2006 Plan to employees, directors, advisors, and consultants providing services to the Company. The 2006 Plan was terminated in connection with the Company’s IPO. Accordingly, no shares are available for future awards under this plan. Outstanding awards under the 2006 Plan continue to be subject to the terms and conditions of the 2006 Plan. The 2006 Plan was administered by the Company’s Board of Directors and the Compensation and Leadership Development Committee of the Board of Directors. The 2006 Plan provides that on the occurrence of certain strategic events, such as a change in control, the vesting of outstanding options shall be accelerated by an amount of time equal to the vesting period that has elapsed prior to such event, whether or not such options are assumed or substituted in the transaction. If the surviving or acquiring corporation does not assume such options, they will terminate prior to the transaction. As of December 31, 2018, there were 10,889,879 shares subject to outstanding stock options under the 2006 Plan. In connection with the Company’s acquisition of Taxcient in 2010, the Company assumed the outstanding stock options issued by Taxcient under the Taxcient Plan, with appropriate adjustments to the number of shares and per share exercise prices in accordance with the merger agreement. At the time of the acquisition, the Company terminated the Taxcient Plan for purposes of future grants. As of December 31, 2018, there were 13,591 Stock-Based Compensation The Company recognized total stock-based compensation cost related to equity incentive awards as follows (in thousands): For the Year Ended December 31, 2018 2017 2016 Stock-based compensation cost: Common stock warrants $ 512 $ 484 $ 372 Stock options 13,279 11,295 7,767 Restricted stock units 90 - - Employee stock purchase plan 2,069 - - Total stock-based compensation cost $ 15,950 $ 11,779 $ 8,139 A small portion of stock-based compensation cost above is capitalized in accordance with the accounting guidance for internal-use software. The Company uses the straight-line attribution method for recognizing stock-based compensation expense. Stock Options The following table summarizes stock option activity for the Company’s stock-based compensation plans for 2018: Weighted Weighted Average Aggregate Average Remaining Intrinsic Exercise Contractual Value Shares Price Life (Years) (in thousands) Options outstanding as of January 1, 2018 10,727,125 $ 9.94 7.00 $ 71,430 Options granted 2,564,528 19.59 Options exercised (1,373,962 ) 7.63 Options cancelled or expired (823,621 ) 13.78 Options outstanding as of December 31, 2018 11,094,070 12.17 6.81 210,523 Options exercisable as of December 31, 2018 6,735,086 $ 9.00 5.63 $ 149,206 A summary of options outstanding and vested as of December 31, 2018 is as follows: Options Outstanding Options Vested and Exercisable Number Weighted Average Number Vested Weighted Average Exercise Prices Outstanding Life (in Years) and Exercisable Life (in Years) $0.70 to $1.90 998,478 2.16 998,478 2.16 2.86 to 6.40 1,173,571 4.27 1,173,571 4.27 8.04 to 11.72 1,476,371 5.23 1,472,047 5.23 12.20 to 15.06 4,696,460 7.56 2,926,377 7.37 16.06 to 24.00 2,558,590 9.12 163,780 8.96 31.99 to 42.21 190,600 9.63 833 9.92 11,094,070 6,735,086 The total intrinsic value of options exercised during 2018, 2017, and 2016 was $17.4 The weighted average grant date fair value of options granted during the years ended December 31, 2018, 2017, and 2016, was $9.07, $6.44, and $5.76 per share, respectively. During the year ended December 31, 2018, 2,002,503 options vested. There were 4,358,984 options unvested as of December 31, 2018. Stock-based compensation cost is recorded on a straight-line basis over the vesting term of each option grant. As of December 31, 2018, $27.6 All stock-based payments to employees are measured based on the grant date fair value of the awards and recognized in the consolidated statements of operations over the period during which the employee is required to perform services in exchange for the award, generally the four-year, straight-line vesting period. For the periods presented, the fair value of options was estimated using the Black-Scholes option-pricing model with the following assumptions: For the Year Ended December 31, 2018 2017 2016 Fair value of common stock $16.86 to $42.21 $13.84 to $16.06 $12.34 to $13.84 Volatility 40% 40% to 43% 40 to 45% Expected term 6 years 6 years 6 years Expected dividend yield n/a n/a n/a Risk-free interest rate 2.55% to 3.10% 2.02% to 2.22% 1.35% to 2.26% The Board of Directors intends all options granted to be exercisable at a price per share not less than the per share fair value of the Company’s common stock underlying those options on the date of grant. Following the closing of the IPO, the fair value per share of the Company’s common stock for purposes of determining stock-based compensation is the closing price of the Company’s common stock as reported on the applicable grant date. Prior to the IPO, the fair value of the common stock underlying stock options and common stock warrants was estimated by the Board of Directors, with input from management and third-party valuation firms. The enterprise value utilized in determining the fair value of common stock for financial reporting purposes was estimated using the market approach and the income approach. Under the market approach, the Company used the guideline public company method, which estimates the fair value of the business enterprise based on market prices of stock of guideline public companies and the option pricing method. Indications of value were estimated by utilizing revenue multiples to measure enterprise value. The guideline merged and acquired company method was not utilized in the valuation, as the Company regarded the method as less reliable as management believed it did not directly reflect the Company’s future prospects. The income approach estimated the enterprise value based on the present value of the Company’s future estimated cash flows and the residual value beyond the forecast period. The residual value was based on an exit (or terminal) multiple observed in the comparable company method analysis. The future cash flows and residual value were discounted to their present value to reflect the risks inherent in the Company achieving these estimated cash flows. The discount rate was based on venture capital rates of return for companies nearing an initial public offering. The discount rate was applied using the mid-year convention. The mid-year convention assumes that cash flows are generated evenly throughout the year, as opposed to in a lump sum at the end of the year. The Company lacks sufficient historical volatility of its stock price. Selected volatility is representative of expected future volatility and was based on the historical and implied volatility of comparable publicly traded companies over a similar expected term. The expected term represents the period that the Company’s stock-based awards are expected to be outstanding. Given the Company’s relative inexperience of significant exercise activity, the expected term assumptions were determined based on application of the simplified method of expected term calculation by averaging the contractual life of option grants and the vesting period of such grants. This application, when coupled with the contractual life of 10 years and average vesting term of 4 years, creates an expected term of 6 years. The Company has not paid and does not expect to pay dividends. The risk-free interest rate was based on the rate for a U.S. Treasury zero-coupon issue with a term that closely approximates the expected life of the option grant at the date nearest the option grant date. Restricted Stock Units The following table summarizes RSU activity for the Company’s stock-based compensation plans for 2018: Weighted Average Grant Date Fair Shares Value Per Share RSUs outstanding as of January 1, 2018 — $ — RSUs granted 74,757 32.69 RSUs vested — — RSUs cancelled (333 ) 33.52 RSUs outstanding as of December 31, 2018 74,424 $ 32.69 Stock-based compensation cost is recorded on a straight-line basis over the vesting term of each RSU grant based on the fair value of the Company’s underlying common stock on the date of grant. As of December 31, 2018, $2.3 2018 Employee Stock Purchase Plan In April 2018, the Company’s Board of Directors adopted the 2018 Employee Stock Purchase Plan (“ESPP”). The ESPP became effective on June 15, 2018, the first trading day of the Company’s common stock. The ESPP is intended to qualify as an employee stock purchase plan under Section 423 of the Internal Revenue Code of 1986, as amended. Purchases will be accomplished through participation in discrete offering periods. The first offering period began on June 15, 2018 and ended on January 31, 2019. Future offering periods will begin on August 1 and February 1 (or such other date determined by the Company’s Board of Directors or Compensation and Leadership Development Committee). Under the ESPP, eligible employees can acquire shares of the Company’s common stock by accumulating funds through payroll deductions. Employees generally are eligible to participate in the ESPP if they are a U.S. employee and are employed for at least 20 hours per week. The Company may impose additional restrictions on eligibility. Eligible employees can select a rate of payroll deduction between 1% and 15% of their compensation. The purchase price for shares of common stock purchased under the ESPP is 85% of the lesser of the fair market value of the Company’s common stock on (i) the first day of the applicable offering period or (ii) the last day of the purchase period in the applicable offering period. An employee’s participation automatically ends upon termination of employment for any reason. The Company initially reserved 996,709 shares of common stock for sale under the ESPP. The aggregate number of shares reserved for sale under the ESPP increases automatically on each January 1, beginning January 1, 2019, by the number of shares equal to least of (i) 1,000,000 shares of common stock, (ii) 1% of the aggregate number of shares of common stock outstanding on December 31st of the immediately preceding calendar year (rounded up to the nearest whole share), and (iii) an amount determined by the Board of Directors. No more than an aggregate of 10,102,525 shares of common stock may be issued over the ten-year term of the ESPP. As of December 31, 2018, there was approximately $0.3 million of unrecognized stock-based compensation cost related to the ESPP that is expected to be recognized over the remaining terms of the initial offering period that ended on January 31, 2019. For 2018, the fair value of ESPP purchase rights was estimated using the Black-Scholes option-pricing model with the following assumptions: December 31, 2018 Fair value of common stock $24.00 to $38.18 Volatility 40% Expected term 0.5 years Expected dividend yield n/a Risk-free interest rate 2.90% to 2.96%

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	11. Income Taxes Domestic and foreign components of loss before income tax are as follows (in thousands): December 31, 2018 2017 2016 Domestic $ (48,949 ) $ (41,575 ) $ (54,743 ) Foreign (27,577 ) (23,770 ) (2,505 ) Total $ (76,526 ) $ (65,345 ) $ (57,248 ) Major components of the income tax provision (benefit) are as follows (in thousands): December 31, 2018 2017 2016 Current: Federal $ — $ — $ — State — — — Foreign 317 87 552 Total current income tax provision 317 87 552 Deferred: Federal (825 ) (368 ) 435 State 64 90 38 Foreign (532 ) (1,028 ) (385 ) Total deferred income tax provision (1,293 ) (1,306 ) 88 Total $ (976 ) $ (1,219 ) $ 640 U.S. Tax Reform On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (the “Tax Act”). The Tax Act made broad and complex changes to the U.S. tax code, including but not limited to, (1) reduction of the U.S. federal corporate tax rate, (2) requiring a one-time transition tax on certain unrepatriated earnings of foreign subsidiaries, (3) a general elimination of U.S. federal income taxes on dividends from foreign subsidiaries, and (4) a new provision designed to tax global intangible low-taxed income (GILTI), which allows for the possibility of using foreign tax credits (FTCs) and a deduction of up to 50 percent to offset the income tax liability (subject to some limitations). On December 22, 2017, the SEC staff issued SAB 118, which provides guidance on accounting for the tax effects of the Tax Act. SAB 118 provides a measurement period that should not extend beyond one year from the Tax Act enactment date for companies to complete the accounting under ASC 740, Income Taxes. The Company applied the guidance in SAB 118 when accounting for the enactment-date effects of the Act in 2017 and throughout 2018. As of December 31, 2017, the Company had not completed its accounting of all the enactment-date income tax effects of the Act, for the following areas: remeasurement of deferred tax assets and liabilities, one-time transition tax, and tax on global intangible low-taxed income. As of December 31, 2017, the Company remeasured certain deferred tax assets and liabilities based on the rates at which they were expected to reverse in the future (which was generally 21%), by recording a provisional amount of $44.8 million, of which $0.7 million impacted deferred tax expense. The remainder of the re-measurement was offset by a valuation allowance resulting in no impact to tax expense. During 2018, the Company adjusted the provisional amount to $0.9 million tax benefit, which is included as a component of income tax expense from continuing operations. At December 31, 2018, the Company completed the accounting for all of the enactment-date income tax effects of the Act. The one-time transition tax is based on total post-1986 earnings and profits (“E&P”). Due to the overall accumulated E&P deficit at the measurement date, the Company did not record a provisional amount for the one-time transition tax liability for each of the foreign subsidiaries. The Company finalized its calculations of the transition tax liability during 2018 and confirmed its position of accumulated E&P deficit and did not record a tax liability for the one-time transition tax. The Act subjects a U.S. shareholder to tax on GILTI earned by certain foreign subsidiaries. An entity can make an accounting policy election to either recognize deferred taxes for temporary basis differences expected to reverse as GILTI in future years or to provide for the tax expense related to GILTI in the year the tax is incurred as a period expense only. Because the Company was evaluating the provision of GILTI as of December 31, 2017, no GILTI-related deferred amounts were recorded in 2017. As of December 31, 2018, the Company has elected to account for GILTI in the year the tax is incurred as a period cost. It is the Company’s intention to reinvest the earnings of non-U.S. subsidiaries in those operations. As of December 31, 2018, the Company has not made a provision for U.S. or additional foreign withholding taxes for any outside basis differences inherent in its investments in foreign subsidiaries that are indefinitely reinvested. It is not practicable to estimate the amount of deferred tax liability related to investments in these foreign subsidiaries. Reconciliation of Provision (Benefit) for Income Taxes Major differences between the U.S. statutory rate (21% for 2018 and 35% for 2017 and 2016) and the effective tax rate are as follows (in thousands): December 31, 2018 2017 2016 Tax at statutory rate $ (16,071 ) $ (22,871 ) $ (20,156 ) State taxes (3,375 ) (2,531 ) (1,863 ) Research and development credits (471 ) (1,460 ) (793 ) Changes in tax law — (840 ) — Stock-based compensation (3,246 ) (3,110 ) 85 Goodwill impairment 3,119 2,903 — Foreign rate differential (2,488 ) 1,815 748 Change in valuation allowance 20,006 21,644 22,118 Intercompany intangible asset sale 1,811 — — Other (261 ) 3,231 501 Total $ (976 ) $ (1,219 ) $ 640 Deferred Tax Assets and Liabilities Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets for financial reporting purposes and the amounts used for income tax purposes. Significant components of the Company’s deferred tax assets and liabilities are as follows (in thousands): December 31, 2018 2017 Deferred tax assets: Net operating loss carryforward $ 91,529 $ 74,215 Share-based compensation 8,219 6,622 Deferred revenue 2,186 2,748 Research and development credit, net of uncertain tax position reserve 4,182 3,586 Other 7,134 2,672 Total deferred tax assets 113,250 89,843 Deferred tax liabilities: Definite lived intangibles (590 ) (2,137 ) Other (5,368 ) (1,714 ) Total deferred tax liabilities (5,958 ) (3,851 ) Net deferred tax assets before valuation allowance 107,292 85,992 Valuation allowance (107,852 ) (87,846 ) Net deferred tax liability $ (560 ) $ (1,854 ) As of December 31, 2018 and 2017, the Company had federal net operating loss carryforwards (“NOLs”) of approximately $342.5 million and $292.2 million, respectively, and state NOLs of approximately $219.2 The Company has assessed its ability to realize its deferred tax assets and has recorded a valuation allowance against such assets to the extent that, based on the weight of all available evidence, it is more likely than not that all or a portion of the deferred tax assets will not be realized. In assessing the likelihood of future realization of its deferred tax assets, the Company placed a significant amount of weight on its history of generating U.S. tax losses, including in the current year. The increase in the valuation allowance each period was primarily related to U.S. federal and state tax losses incurred during the period. Accounting for Uncertainty in Income Taxes The Company has established an accrual for uncertain tax positions related to its U.S. research and development credits and for the valuation of intellectual property transferred between international entities. As of December 31, 2018 and 2017, the Company had $4.1 million and $3.3 million of unrecognized tax benefits, of which the total amount that would impact the effective tax rate, if recognized, is $0.2 million. The Company has not recorded any interest or penalties related to its unrecognized tax benefits. However, any such amounts recorded in the future will be classified as a component of income tax expense. The Company does not believe it is reasonably possible that its unrecognized tax benefits will significantly change in the next twelve months. A reconciliation of the beginning and ending balances for unrecognized tax benefits is as follows (in thousands): December 31, 2018 2017 2016 Balance at January 1 $ 3,300 $ 2,727 $ 3,796 Additions for tax positions related to the current year 1,446 867 242 Additions for tax positions related to prior years — — — Reductions for tax positions related to prior years (628 ) (294 ) (1,311 ) Reductions related to settlements — — — Reductions related to a lapse of statute — — — Balance at December 31 $ 4,118 $ 3,300 $ 2,727 The Company files income tax returns in the U.S. federal jurisdiction, and various state and foreign jurisdictions. No U.S. federal income tax payments were made due to the Company’s NOL position. The Company made income tax payments of $0.4 million, $0.4 million, and $0.3 million related to the operations of its foreign subsidiaries for the years ended December 31, 2018, 2017, and 2016, respectively. With limited exceptions, all tax years for which the Company has filed a tax return remain open due to the existence of NOLs.

Net Loss Per Share Attributable

Net Loss Per Share Attributable to Common Shareholders	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Net Loss Per Share Attributable to Common Shareholders	12. Net Loss Per Share Attributable to Common Shareholders The Company calculates basic and diluted net loss per share attributable to common shareholders in conformity with the two-class method required for companies with participating securities. The Company considered all series of convertible preferred stock to be participating securities. Under the two-class method, the net loss attributable to common shareholders was not allocated to the convertible preferred stock as the holders of convertible preferred stock did not have a contractual obligation to share in losses. The diluted net loss per share attributable to common shareholders is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. For purposes of this calculation, all common stock equivalents have been excluded from the calculation of diluted net loss per share attributable to common shareholders as their effect is antidilutive. As a result, basic and diluted net loss per common share was the same for each period presented. The following table sets forth the computation of basic and diluted net loss per common share (in thousands, except per share amounts): Year Ended December 31, 2018 2017 2016 Numerator: Net loss attributable to common shareholders $ (75,550 ) $ (64,126 ) $ (57,888 ) Denominator: Weighted-average common shares outstanding-basic 38,692 5,632 5,706 Dilutive effect of share equivalents resulting from stock options, common stock warrants and convertible preferred shares (as converted) — — — Weighted-average common shares outstanding-diluted 38,692 5,632 5,706 Net loss per common share, basic and diluted $ (1.95 ) $ (11.39 ) $ (10.15 ) The following weighted-average outstanding shares of common stock equivalents were excluded from the computation of diluted net loss per share attributable to common shareholders for the periods presented because the impact of including them would have been antidilutive (in thousands): Year Ended December 31, 2018 2017 2016 Options to purchase common shares 11,271 10,507 8,653 Unvested restricted stock units 9 — — Employee stock purchase plan shares 71 — — Common stock warrants 236 580 679 Convertible preferred shares (as converted) 23,562 50,893 47,185 Preferred stock warrants — — 26 Total 35,149 61,980 56,543

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent Events On January 10, 2019, the Company entered into an office lease agreement in Pune, India to replace several existing office leases, which expire incrementally beginning in September 2019 through July 2022. Minimum lease payments over the 60-month lease term, which begins May 2019, are approximately $7.3 million. Minimum lease payments do not include the Company’s proportionate share of any operating expenses. The lease agreement also required a $0.8 million refundable security deposit. On January 22, 2019, the Company acquired the operating assets of Compli, Inc., a provider of compliance services, technology, and software to producers, distributors, and importers of alcoholic beverages in the United States. Total cash consideration for the purchase was $13.2 million at closing. The purchase agreement provides for additional consideration of up to $4.0 million under an earnout provision. The earnout amount is based on revenue recognized by the Company from the acquired operating assets for the twelve-month period ending January 31, 2020. On February 6, 2019, the Company acquired intellectual property and other assets of Indix Corporation, an artificial intelligence company providing comprehensive product descriptions for more than one billion products sold and shipped worldwide. Total cash consideration for the purchase was $7.1 million at closing. The purchase agreement provides for additional consideration to be paid of up to $3.0 million under an earnout provision. The earnout amount is based on the successful transition and achievement of development milestones established in the purchase agreement. These milestones conclude by February 6, 2020.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Initial Public Offering	Initial Public Offering In June 2018, the Company completed an initial public offering (“IPO”), in which the Company sold 8,625,000 shares of its common stock, including the full exercise of the underwriters’ option to purchase 1,125,000 additional shares of common stock, at the initial price to the public of $24.00 per share. The Company received net proceeds of $192.5 million, after deducting underwriting discounts and commissions and before deducting offering expenses paid and payable by the Company of $3.4 million. Immediately prior to the closing of the IPO, (1) all outstanding shares of preferred stock converted into shares of the Company’s common stock on a 2-to-1 basis, and (2) common stock warrants then outstanding were automatically net exercised into shares of the Company’s common stock. As of December 31, 2018, 66,768,563 shares of the Company’s common stock were outstanding.
Reverse Stock Split and Conversion of Series Preferred Stock	Reverse Stock Split and Conversion of Series Preferred Stock On May 10, 2018, the Company effected a 2-to-1 reverse stock split of outstanding common stock, including outstanding stock options and common stock warrants. At the same time, the Company amended its amended and restated articles of incorporation to trigger the automatic conversion of the Series Preferred Stock immediately prior to the closing of the IPO. As a result of the reverse stock split, the applicable conversion price was increased for each series of outstanding Series Preferred Stock. The increased conversion price effectively resulted in a 2-to-1 conversion ratio of Series Preferred Stock to common stock. All common share and per common share amounts for all periods presented in these consolidated financial statements and notes thereto, have been adjusted retrospectively, where applicable, to reflect the reverse stock split. Series Preferred Stock amounts have been adjusted retrospectively only where the conversion to common stock is presented.
Accounting Principles	Accounting Principles The consolidated financial statements and accompanying notes were prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”).
Principles of Consolidation	Principles of Consolidation The accompanying consolidated financial statements include those of the Company and its subsidiaries after elimination of all intercompany accounts and transactions.
Segments	Segments The Company operates its business as one operating segment. Operating segments are defined as components of an enterprise about which separate financial information is evaluated regularly by the chief operating decision maker, the Company’s Chief Executive Officer, in deciding how to allocate resources and assess performance. The Company’s chief operating decision maker allocates resources and assesses performance based upon discrete financial information at the consolidated level. For the years ended December 31, 2018, 2017, and 2016, approximately 6%, 5%, and 3% of the Company’s revenues were generated outside of the United States, respectively. As of December 31, 2018 and 2017, approximately 7% and 11% of the Company’s long-lived assets were held outside of the United States. As of December 31, 2018 and 2017, approximately 3% and 5% of the Company’s long-lived assets were held in the United Kingdom.
Use of Estimates	Use of Estimates The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Significant estimates include: the standalone value of each element in multiple-element arrangements for revenue recognition; the allowance for doubtful accounts; the measurement of fair values of stock-based compensation award grants; the expected earnout obligations in connection with acquisitions; the expected term of the customer relationship for activation, integration, and setup fee activity (collectively, the “setup fee”); the valuation of acquired intangible assets; and the valuation of the fair value of reporting units for analyzing goodwill. Actual results could materially differ from those estimates.
Risks and Uncertainties	Risks and Uncertainties The Company has incurred significant operating losses since its inception, including net losses of $75.6 million, $64.1 million, and $57.9 million for the years ended December 31, 2018, 2017, and 2016, respectively. The Company had an accumulated deficit of $487.6 million and $412.1 million as of December 31, 2018 and 2017, respectively. The Company believes that its cash and cash equivalents of $142.3 million as of December 31, 2018 and the availability under its revolving credit facility, as is further outlined in Note 8, are adequate to satisfy its current obligations.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. A three-level fair value hierarchy prioritizes the inputs used to measure fair value. The hierarchy requires entities to maximize the use of observable inputs and minimize the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows: • Level 1 • Level 2 • Level 3 The Company’s assessment of the significance of an input to the fair value measurement requires judgment, which may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels. The carrying amounts reported in the consolidated financial statements approximate the fair value for cash equivalents, trade accounts receivable, trade payables, and accrued expenses, due to their short-term nature. The carrying amount of the Company’s term loan and revolving credit facility, to the extent there is a carrying amount as of the balance sheet date, approximates fair value, considering the interest rates are based on the prime interest rate.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include highly liquid securities with original maturities of three months or less and are carried at cost, which approximates market value given their short-term nature.
Customer Funds Assets and Obligations	Customer Funds Assets and Obligations Funds Held from Customers The Company maintains trust accounts with financial institutions, which allows customers to outsource their tax remittance functions to the Company. The Company has legal ownership over the accounts utilized for this purpose. Funds held from customers represents cash and cash equivalents that, based upon the Company’s intent, are restricted solely for satisfying the obligations to remit funds relating to the Company’s tax remittance services. Funds held from customers are not commingled with the Company’s operating funds but are typically deposited with funds also held on behalf of other customers of the Company. Funds held from customers are deposited in accounts at FDIC-insured institutions. Funds held from customers were $13.1 million as of both December 31, 2018 and 2017. Receivables from Customers Occasionally, the Company will pay a tax obligation to taxing authorities on behalf of its customer, prior to receiving funds from the customer or prior to receiving the refund due to the customer from the taxing authority. Accounts receivable from customers represent amounts the customer is contractually obligated to repay to the Company. The future economic benefit to the Company is restricted solely for the repayment of customer funds and taxing authority obligations. Receivables from customers deemed uncollectible are charged against a separate allowance for doubtful accounts. The allowance against receivables from customers is a result of the Company assuming credit risk associated with its customers’ tax remittance obligations. The table below details the allowance against receivables from customers (in thousands): December 31, 2018 2017 2016 Balance at the beginning of the year $ 666 $ 754 $ 266 Charged to expense (83 ) (88 ) 517 Write-offs (385 ) - (29 ) Balance at the end of the year $ 198 $ 666 $ 754 Customer Funds Obligations Customer funds obligations represent the Company’s contractual obligations to remit collected funds to satisfy customer tax payments. Customer funds obligations are reported as a current liability on the consolidated balance sheets, as the obligations are expected to be settled within one year. Customer Funds Assets and Obligations in Consolidated Statement of Cash Flows Cash flows related to the cash received from and paid on behalf of customers are reported as follows: (1) changes in customer funds obligations liability are presented as cash flows from financing activities; (2) changes in customer funds asset (e.g., customer funds held in cash and cash equivalents and receivable from customers and taxing authorities) are presented as net cash flows from investing activities; and (3) changes in customer funds asset account that relate to activities paying for the trust operations, such as banking fees, are included as cash flows from operating activities.
Trade Accounts Receivable	Trade Accounts Receivable Trade accounts receivable represent amounts due from customers when the Company has invoiced the customer and has not yet received payment. An invoice is issued when the customer is contractually obligated to pay for software subscriptions and/or services. Trade accounts receivable are presented net of an allowance for doubtful accounts. The allowance for doubtful accounts is the Company’s best estimate of the amount of probable credit losses in existing trade accounts receivable. The allowance for doubtful accounts is based on the assessment of collectability. The Company regularly reviews the adequacy of the allowance for doubtful accounts by considering several factors, including the age of each outstanding invoice and the collection history of each customer. Trade accounts receivable are recorded to bad debt expense when deemed uncollectible based on either a specific identification or the age of the receivable. The table below details the allowance for doubtful accounts (in thousands): December 31, 2018 2017 2016 Balance at the beginning of the year $ 905 $ 1,324 $ 1,154 Charged to expense (183 ) (105 ) 2,390 Write-offs (201 ) (314 ) (2,220 ) Balance at the end of the year $ 521 $ 905 $ 1,324
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk are primarily cash, cash equivalents, accounts receivable, and funds held from customers, which are held in financial institutions management believes have a high credit standing. To manage credit risk related to accounts receivable, the Company evaluates customers’ financial condition and generally collateral is not required. As of December 31, 2018 and 2017, there were no customers that represented more than 10% of the Company’s net trade accounts receivable or more than 10% of the Company’s revenue in any of the periods presented.
Property and Equipment	Property and Equipment Property and equipment are stated at cost less accumulated depreciation. Depreciation on property and equipment is computed on the straight-line method over the estimated useful life of the asset or the lease term (for leasehold improvements), whichever is shorter. Upon retirement or sale, the cost of the disposed asset and the related accumulated depreciation are removed and any resulting gain or loss is recorded in the consolidated statements of operations. Maintenance and repairs that do not improve or extend the lives of the respective assets are charged to expense in the period incurred.
Research and Development	Research and Development Research and development expenses consist primarily of personnel and related expenses for the Company’s research and development staff, including salaries, benefits, bonuses and stock-based compensation, and allocated overhead. Expenditures for research and development are expensed as incurred.
Software Capitalization	Software Capitalization Software development costs for hosting customer transactions (i.e., cloud-based software solutions) are capitalized once the project is in the application development stage in accordance with the accounting guidance for internal-use software. These capitalized costs include external direct costs of services consumed in developing or obtaining the software and personnel expenses for employees who are directly associated with the development. Capitalization of these costs concludes once the project is substantially complete and the software is ready for its intended purpose. Post-configuration training and maintenance costs are expensed as incurred. For the years ended December 31, 2018, 2017, and 2016, $1.1 million, $1.0 million, and $0.8 million software development costs were capitalized, respectively. Capitalized software development costs are amortized on a straight-line basis over the estimated useful life, generally 6 years. In circumstances where software is developed for both cloud-based software solutions and for the purpose of being sold, leased or otherwise marketed (i.e., customer hosted software), capitalization of development costs occurs after technological feasibility of the software is established and continues until the product is available for general release to customers. Since the Company’s developed software is available for general release concurrent with the establishment of technological feasibility, development costs are not capitalized in these circumstances.
Acquisitions and Goodwill	Acquisitions and Goodwill The Company’s identifiable assets acquired and liabilities assumed in a business combination are recorded at their acquisition date fair values. The valuation requires management to make significant estimates and assumptions, especially with respect to long-lived and intangible assets. Critical estimates in valuing intangible assets include, but are not limited to: • future expected cash flows from customer agreements, customer lists, distribution agreements, and proprietary technology and non-compete agreements; • assumptions about the length of time the brand will continue to be used in the Company’s suite of solutions; and • discount rates used to determine the present value of recognized assets and liabilities. The Company’s estimates of fair value are based upon assumptions it believes to be reasonable, but that are inherently uncertain and unpredictable. Assumptions may be incomplete or inaccurate, and unanticipated events and circumstances may occur. Goodwill is calculated as the excess of the purchase price over the fair value of net assets, including the amount assigned to identifiable intangible assets. Acquisition-related costs, including advisory, legal, accounting, valuation, and other costs, are expensed in the periods in which these costs are incurred. The results of operations of an acquired business are included in the consolidated financial statements beginning at the acquisition date. Goodwill is tested for impairment annually on October 31, or in the event of certain occurrences. Goodwill impairments of $9.2 million and $8.4 million were recorded for the years ended December 31, 2018 and 2017, respectively (See Note 6). There was no goodwill impairment recorded for the year ended December 31, 2016. The Company estimates the fair value of the acquisition-related earnout using various valuation approaches, as well as significant unobservable inputs, reflecting the Company’s assessment of the assumptions market participants would use to value these liabilities. The fair value of the earnout is remeasured each reporting period, with any change in the value recorded as other income or expense. The Company recorded income of $0.4 million and $0.7 million, and expense of $0.3 million for the years ended December 31, 2018, 2017, and 2016, respectively.
Long-Lived Assets	Long-Lived Assets The Company evaluates long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of these assets may not be recoverable. An impairment is recognized in the event the carrying value of such assets exceeds their fair value. If the carrying value exceeds the fair value, then an impairment test is performed to determine the fair value. In 2018, the Company evaluated the long-lived intangible assets in the Company’s Brazilian reporting unit for impairment as a result of an interim triggering event discussed in Note 6. No impairment of long-lived assets (other than goodwill as discussed in Note 6), including those in the Brazilian reporting unit, occurred in 2018. See Restructuring Charges for impairment recorded in 2017. No impairment of long-lived assets occurred in 2016.
Acquired Intangible Assets	Acquired Intangible Assets Acquired intangible assets consist of developed technology, customer relationships, noncompetition agreements, and tradenames and trademarks, resulting from the Company’s acquisitions. Acquired intangible assets are recorded at fair value on the date of acquisition and amortized over their estimated useful lives on a straight-line basis. Acquisition-related costs, primarily legal fees, are capitalized and included in the cost basis of the intangible asset when incurred. The Company recognizes an earnout liability for acquisitions of intangible assets that are accounted for as an asset acquisition when the liability is earned and the amount is known. The earnout liability is capitalized as part of the cost of the assets acquired and amortized over the remaining useful life of the asset.
Income Taxes	Income Taxes The Company’s deferred tax assets are determined based on temporary differences between the financial reporting and income tax basis of assets and liabilities and are measured using the tax rates that will be in effect when the differences are expected to reverse. A valuation allowance is recorded when it is more likely than not that some of the deferred tax assets will not be realized. The Company assesses its income tax positions and records tax benefits based upon management’s evaluation of the facts, circumstances, and information available at the reporting date. The objectives of accounting for income taxes are to recognize the amount of taxes payable or refundable for the current year and deferred tax liabilities and assets for the future tax consequences of events that have been recognized in an entity’s financial statements or tax returns. The Company will 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 the financial statements from such a position are measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. Judgment is required in assessing the future tax consequences of events that have been recognized in the Company’s consolidated financial statements or tax returns. Variations in the actual outcome of these future tax consequences could materially impact the consolidated financial statements. The Company accounted for the tax effects of The Tax Cuts and Jobs Act (the “Tax Act”), enacted on December 22, 2017, on a provisional basis as of December 31, 2017. The Company completed its accounting during the one-year measurement period from enactment ending December 31, 2018. See Note 11 for further discussion of impacts of the Tax Act.
Revenue Recognition	Revenue Recognition The Company primarily generates revenue from fees paid for subscriptions to tax compliance solutions and fees paid for services performed in preparing and filing tax returns on behalf of its customers. Amounts that have been invoiced are recorded in accounts receivable and deferred revenue or revenue, depending upon whether the revenue recognition criteria have been met. In most instances, the initial arrangement with customers includes multiple elements, comprised of subscription and/or professional services, along with non-refundable upfront fees for new customers. The Company evaluates each element in a multiple-element arrangement to determine whether it represents a separate unit of accounting. An element constitutes a separate unit of accounting when the delivered item has standalone value and delivery of the undelivered element is probable and within the Company’s control. Other than nonrefundable upfront fees, the Company’s services typically have standalone value because they are routinely sold separately. Professional services also have standalone value because there are third party vendors that provide similar professional services to customers on a standalone basis. If one or more of the deliverables does not have standalone value upon delivery, the deliverables that do not have standalone value are generally combined with the final deliverable within the arrangement and treated as a single unit of accounting. Revenue for arrangements treated as a single unit of accounting is generally recognized over the period beginning upon delivery of the final deliverable and continuing over the remaining term of the subscription contract. The Company allocates revenue to each element in an arrangement based on the selling price hierarchy. The selling price for a deliverable is based on its vendor-specific objective evidence (“VSOE”), if available, third-party evidence (“TPE”), or best estimate of selling price (“BESP”), if neither VSOE nor TPE is available. As the Company has been unable to establish VSOE or TPE for the elements of its arrangements, the Company establishes the BESP for each element. The determination of BESP requires significant estimates and judgments. BESP is determined by considering the Company’s overall pricing objectives and current market conditions. Other factors considered include existing pricing and discounting practices, historical comparisons of contract prices to list prices, customer demographics, and gross margin objectives. Revenue recognition begins when all the following criteria are met: • There is persuasive evidence of an arrangement; • The product or service is delivered to the customer; • The amount of fees to be paid by the customer is fixed or determinable; and • The collection of the fees is reasonably assured. Sales and other taxes collected from customers to be remitted to the taxing jurisdiction are excluded from revenues.
Subscription and Returns Revenue	Subscription and Returns Revenue Subscription and returns revenue primarily consists of contractually agreed upon fees paid for using the Company’s cloud-based solutions and fees paid for preparing and filing transaction tax returns on behalf of customers. Under the Company’s subscription agreements, customers select a price plan that includes an allotted number of maximum transactions over the subscription term. Unused transactions are not carried over to the customer’s next subscription term, and customers are not entitled to refund of fees paid or relief from fees due in the event they do not use the allotted number of transactions. If customers exceed the maximum transaction level within their price plan, the Company will generally upgrade the customer to a higher transaction price plan or, in some cases, charge overage fees on a per transaction basis. The Company’s subscription arrangements do not provide the customer with the right to take possession of the software supporting the cloud-based application services. The Company’s subscription contracts are generally non-cancelable except where contract terms provide rights to cancel in the first 60 days of the contract term. The Company reserves for estimated cancellations based on actual history. Current history of customer cancellations has not had a significant impact on revenue recognized. The Company invoices its subscription customers for the initial term at contract signing and at each subscription renewal. Initial terms generally range from twelve to eighteen months, and renewal periods are typically one year. Amounts that are contractually billable and have been invoiced, or which have been collected as cash are initially recorded as deferred revenue. While most of the Company’s customers are invoiced once at the beginning of the term, a portion of customers are invoiced quarterly or monthly. Tax returns processing services include collection of tax data and amounts, preparation of all compliance forms, and submission to taxing authorities. Returns processing services are charged on a subscription basis for an allotted number of returns to process within a given time period or per return filing. The consideration allocated to a returns subscription is recognized as revenue over the contract period commencing when the subscription services are made available to the customer. The Company recognizes revenue when the return is filed when sold on a per return filing basis. Included in the total subscription fee for cloud-based solutions are non-refundable upfront fees that are typically charged to each of the Company’s new customers. These fees are associated with work performed to set up a customer with the Company’s services, and do not have standalone value. The Company recognizes revenue for these fees over the expected term of the customer relationship, beginning when services commence. As of January 1, 2016, and through December 31, 2018, the Company estimated an expected customer relationships term of 6 years. The Company continues to evaluate the expected customer life and it is possible that the expected term of customer relationships may change in future periods. Included in subscription and returns revenue is interest income on funds held for customers. The Company uses trust accounts at FDIC-insured institutions to provide tax remittance services to customers and collect funds from customers in advance of remittance to tax authorities. Prior to remittance, the Company earns interest on these funds. The interest income earned on funds held for customers was $1.1 million for the year ended December 31, 2018. Prior to April 1, 2018, the Company did not earn interest on these funds.
Professional Services Revenue	Professional Services Revenue The Company bills for service arrangements on a fixed fee or time and materials basis. Professional services revenue includes fees from providing tax analysis, configurations, data migrations, integration, training, and other support services. The consideration allocated to professional services is recognized as revenue when services are performed and are collectable under the terms of the associated contracts.
Deferred Revenue	Deferred Revenue Deferred revenue consists of customer billings and payments in advance of revenue being recognized from the Company’s contracts. The Company typically invoices its customers annually in advance for its subscription-based contracts. Deferred revenue and accounts receivable are recorded at the beginning of the new subscription term. For some customers, the Company invoices in monthly, quarterly, or multi-year installments and, therefore, the deferred revenue balance does not necessarily represent the total contract value of all non-cancelable subscription agreements. Deferred revenue anticipated to be recognized during the succeeding 12-month period is recorded as current deferred revenue and the remaining portion is recorded as noncurrent deferred revenue.
Integration and Referral Partner Commissions	Integration and Referral Partner Commissions The Company utilizes independent partners to build and maintain integrations for business applications, such as accounting, ERP, ecommerce, POS, recurring billing, and CRM systems. These integrations link the business application to the Company’s cloud-based software solutions. Integration partners are paid a commission based on a percentage of the sales that use the integration. In general, integration partners are paid a higher commission for the initial sale to a new customer and a lower commission for renewal sales. Referral partners bring new customers to the Company and receive a commission that is based on a percentage of the first-year sales. Some of the Company’s integration partners also refer customers that have purchased the partner’s business application. The Company recognizes commissions related to integration and referral partners in sales and marketing costs when a binding customer order is agreed to by the Company and the customer. The Company expenses partner commissions as incurred and classifies these costs as sales and marketing expenses. Partner commissions totaled $21.7 million, $14.3 million, and $9.9 million for the years ended December 31, 2018, 2017, and 2016, respectively. An immaterial portion of the Company’s revenue is generated from sales made through integration partners, rather than through the Company. For these transactions, the Company evaluates whether revenue should be presented on a gross basis, which is the amount that a customer pays for the Company’s solution, or on a net basis, which is the customer payment less partner commissions. The Company has determined that a gross presentation is appropriate for revenue generated through these integration partners, because the Company is the primary provider of services to the end customers and is the primary obligor in these relationships. In addition, the Company has customer credit risk for non-payment, and the Company has latitude in establishing and negotiating prices on transactions from these sources.
Cost of Revenue	Cost of Revenue Cost of revenue consists of personnel and related expenses for providing the Company’s solutions and supporting its customers, including salaries, benefits, bonuses, and stock-based compensation, direct costs and allocated costs associated with information technology, tax content, and allocated rent and overhead.
Advertising Costs	Advertising Costs The Company expenses all advertising costs as incurred and classifies these costs as sales and marketing expenses. Advertising expenses were $18.8 million, $22.7 million, $19.6 million for the years ended December 31, 2018, 2017, and 2016, respectively.
Leases	Leases The Company is a lessee of facilities in the United States, Canada, United Kingdom, Belgium, Brazil, and India and certain other equipment under non-cancelable lease agreements. The Company categorizes leases at their inception as either operating or capital leases. For certain lease agreements, the Company may receive rent holidays and other incentives, including allowances for leasehold improvements. Future operating lease payments are recognized as rent expense on a straight-line basis without regard to deferred payment terms, such as rent holidays. Incentives received are treated as a reduction of rent expense over the term of the agreement. Leasehold improvements are capitalized at cost and amortized over the lesser of their estimated useful life or the term of the lease.
Foreign Currency Translation	Foreign Currency Translation Assets and liabilities of each of the Company’s foreign subsidiaries are translated at the exchange rate in effect at each period-end. Consolidated statement of operations amounts are translated at the average rate of exchange prevailing during the period. Translation adjustments arising from differing exchange rates from period to period are included in accumulated other comprehensive income (loss) within shareholders’ equity (deficit).
Employee Benefit Plan	Employee Benefit Plan The Company offers a salary deferral 401(k) plan for its U.S. employees. The plan allows employees to contribute a percentage of their pretax earnings annually, subject to limitations imposed by the Internal Revenue Service. The plan also allows the Company to make a matching contribution, subject to certain limitations. The Company contributed $0.8 million, $0.7 million, and $0.6 million to the plan in 2018, 2017, and 2016, respectively.
Stock-Based Compensation	Stock-Based Compensation The Company accounts for stock-based compensation by calculating the fair value of each stock option, common stock warrant, restricted stock unit (“RSU”), or purchase right issued under the Company’s 2018 Employee Stock Purchase Plan (“ESPP”) at the date of grant. The fair value of stock options, common stock warrants, and purchase rights issued under the ESPP is estimated by applying the Black-Scholes option-pricing model. This model uses the fair value of the Company’s underlying common stock at the measurement date, the expected or contractual term of the option, the expected volatility of its common stock, risk-free interest rates, and expected dividend yield of its common stock. The fair value of an RSU is determined using the fair value of the Company’s underlying common stock on the date of grant. Beginning January 1, 2017, the Company accounts for forfeitures as they occur.
Deferred Financing Costs	Deferred Financing Costs Deferred financing costs, consisting primarily of legal, accounting, printing and filing services, and other direct fees and costs related to public offering of common stock, are capitalized. As of December 31, 2018 and 2017, $0.6 million and $1.6 million of deferred financing costs were recorded in prepaid expenses and other current assets, respectively. The deferred financing costs related to the IPO were offset against proceeds from the IPO upon the closing of the offering in June 2018.
Restructuring Charges	Restructuring Charges In August 2017, management approved a plan to close the Company’s Overland Park office and consolidate these operations into the Seattle and Durham locations. The restructuring plan was completed March 31, 2018. In connection with this plan, the Company incurred restructuring charges of $0.8 million in 2017, including $0.7 million of termination benefits and other reorganization costs, primarily associated with integrating the operations and $0.1 million related to an impairment loss on fixed assets. No restructuring liability remained as of December 31, 2018. As of December 31, 2017, $0.6 million of restructuring liability remained. Restructuring charges associated with this plan are included in restructuring charges in the consolidated statement of operations. Accrued termination benefits are recorded in accrued payroll and related taxes on the consolidated balance sheet. The accrued termination benefit balance as of December 31, 2017 was paid within one year.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements As an “emerging growth company,” the Jumpstart Our Business Startups Act, or the JOBS Act, allows the Company to delay adoption of new or revised accounting pronouncements applicable to public companies until such pronouncements are made applicable to private companies. The Company has elected to use the adoption dates applicable to private companies. As a result, the Company’s financial statements may not be comparable to the financial statements of issuers who are required to comply with the effective date for new or revised accounting standards that are applicable to public companies. Recently Adopted Accounting Standards In January 2017, the FASB issued ASU No. 2017-01 which clarifies the definition of a business. The guidance in ASU No. 2017-01 is required for annual reporting periods beginning after December 15, 2018 for business entities that are not public, with early adoption permitted. The Company early adopted ASU No. 2017-01 in conjunction with the asset acquisitions outlined in Note 6. In October 2016, the FASB issued ASU No. 2016-16, which modifies the accounting for income taxes consequences of intra-entity transfers of assets other than inventory. The guidance in ASU No. 2016-16 is required for annual reporting periods beginning after December 15, 2018 for business entities that are not public, with early adoption permitted. The Company early adopted ASU No. 2016-16 in conjunction with an intra-entity transfer of intellectual property that occurred in the fourth quarter of 2018. The adoption had an immaterial impact on the consolidated financial statements. In March 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-09, related to Compensation—Stock Compensation (“Topic 718”). This standard makes several modifications to Topic 718 related to the accounting for forfeitures, employer tax withholding on share-based compensation and the financial statement presentation of excess tax benefits or deficiencies. ASU No. 2016-09 also clarifies the statement of cash flows presentation for certain components of share-based awards. The standard is effective for interim and annual reporting periods beginning after December 15, 2017, for business entities that are not public, although early adoption is permitted. The Company early adopted ASU No. 2016-09 on January 1, 2017. The Company elected to account for forfeitures upon occurrence and the net cumulative-effect was recognized as a $0.1 million increase to additional paid-in capital and a $0.1 million increase to accumulated deficit upon adoption. Also upon adoption, the Company recorded a $11.3 million cumulative-effect adjustment decrease in accumulated deficit and an offsetting increase in deferred tax assets for previously unrecognized excess tax benefits that existed as of January 1, 2017. Since the realization of these deferred tax assets is not more likely than not to be recovered, in 2017 the Company recorded a $11.3 million valuation allowance against these deferred tax assets with an offsetting increase in accumulated deficit. In January 2017, the FASB issued ASU No. 2017-04, which eliminates step two from the goodwill impairment test. Under the amendments in ASU No. 2017-04, an entity should recognize an impairment charge for the amount by which the carrying amount of a reporting unit exceeds its fair value. However, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. ASU No. 2017-04 is effective for the Company in the first quarter of fiscal 2021 on a prospective basis, and earlier adoption is permitted for goodwill impairment tests performed after January 1, 2017. The Company adopted ASU No. 2017-04 on January 1, 2017. See Note 6 for further details. New Accounting Standards Not Yet Adopted In May 2014, the FASB issued ASU No. 2014-09 which, along with subsequent ASUs, amends the existing accounting standards for revenue recognition. This guidance is based on principles that govern the recognition of revenue at an amount an entity expects to be entitled to receive when products are transferred to customers. ASU No. 2014-09 is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period for public business entities, and for annual reporting periods beginning after December 15, 2018 for business entities that are not public. This guidance may be applied retrospectively to each prior period presented or retrospectively with the cumulative effect recognized as of the date of adoption. Additionally, the new guidance requires enhanced disclosures, including revenue recognition policies to identify performance obligations to customers and significant judgments in measurement and recognition. The Company has been assessing the impact of the adoption on its consolidated financial statements and accompanying disclosures in the footnotes to the financial statements. The adoption will change revenue recognition for non-refundable upfront fees charged to new customers. Currently, the Company recognizes revenue for these fees over the expected term of the customer relationship. Under the new guidance, the transaction price should be allocated to distinct performance obligations. Because upfront fees do not represent a distinct performance obligation, any such fees will be recognized over the period in which distinct performance obligations in the contract are satisfied, which is expected to be the subscription term. The Company is finalizing its analysis and the adoption of this guidance is expected to result in a reduction of approximately $11.0 to $15.0 million of deferred revenue from the consolidated balance sheet upon adoption. The adoption will also require capitalization of certain costs of obtaining a contract that are currently expensed, such as certain employee sales commissions and partner commissions. These capitalized costs of obtaining a contract will be amortized over the expected period of benefit, which we consider to be the average customer life of six years. The Company expects to capitalize between $18.0 million and $22.0 million of contract costs (e.g., deferred commissions). The Company does not expect the adoption of ASU No. 2014-09 to have any impact on its operating cash flow. The Company will adopt and implement the new revenue recognition guidance, effective January 1, 2019, using the modified retrospective approach. In February 2016, the FASB issued ASU No. 2016-02 which requires lessees to generally recognize most operating leases on the balance sheets but record expenses on the income statements in a manner similar to current accounting. The guidance is effective in 2020 for business entities that are not public with early adoption permitted. The Company is currently evaluating the impact this guidance will have on the Company’s financial statements. The Company currently expects that most operating lease commitments will be subject to the new standard and will be recognized as operating lease liabilities and right-of-use assets upon adoption. While the Company has not yet quantified the impact, these adjustments will increase total assets and total liabilities relative to such amounts reported prior to adoption. In August 2016, the FASB issued ASU No. 2016-15, related to classification of certain cash receipts and payments. ASU No. 2016-15 is intended to add or clarify guidance on the classification of certain cash receipts and payments in the statement of cash flows and to eliminate the diversity in practice related to such classifications. The guidance in ASU No. 2016-15 is required for annual reporting periods beginning after December 15, 2018 for business entities that are not public, with early adoption permitted. The Company adopted the guidance on January 1, 2019. The adoption had no impact on the consolidated financial statements. In June 2018, the FASB issued ASU No. 2018-07, related to stock compensation for nonemployee share-based awards. ASU No. 2018-07 expands the scope of Topic 718 – Compensation – Stock Compensation to include share-based payments issued to nonemployees in order to align the accounting for employees and nonemployees. The guidance in ASU No. 2018-07 is required for annual reporting periods beginning after December 15, 2019 for business entities that are not public, with early adoption permitted. The Company currently intends to early adopt the guidance as of January 1, 2019. The Company does not believe the adoption will have a material impact on the consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-15, related to implementation costs incurred in a cloud computing arrangement that is a service contract. The guidance in ASU No. 2018-15 is required for annual reporting periods beginning after December 15, 2020, for business entities that are not public, with early adoption permitted. The Company is currently evaluating the impact this guidance will have on the Company’s financial statements.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Allowance for Doubtful Accounts	The table below details the allowance against receivables from customers (in thousands): December 31, 2018 2017 2016 Balance at the beginning of the year $ 666 $ 754 $ 266 Charged to expense (83 ) (88 ) 517 Write-offs (385 ) - (29 ) Balance at the end of the year $ 198 $ 666 $ 754 The table below details the allowance for doubtful accounts (in thousands): December 31, 2018 2017 2016 Balance at the beginning of the year $ 905 $ 1,324 $ 1,154 Charged to expense (183 ) (105 ) 2,390 Write-offs (201 ) (314 ) (2,220 ) Balance at the end of the year $ 521 $ 905 $ 1,324

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis	The fair value measurements of assets and liabilities recognized in the accompanying consolidated balance sheets measured at fair value on a recurring basis and the level within the fair value hierarchy in which the fair value measurements fall on dates presented as follows (in thousands): Fair Value Measurements Using Quoted Prices Significant in Active Other Significant Markets for Observable Unobservable Fair Identical Assets Inputs Inputs December 31, 2018 Value (Level 1) (Level 2) (Level 3) Money market funds $ 138,483 $ 138,483 Earnout related to acquisitions — Fair Value Measurements Using Quoted Prices Significant in Active Other Significant Markets for Observable Unobservable Fair Identical Assets Inputs Inputs December 31, 2017 Value (Level 1) (Level 2) (Level 3) Money market funds $ 10,261 $ 10,261 $ $ Earnout related to acquisitions 380 380
Summary of Reconciliation of Beginning and Ending Balances of Recurring Fair Value Measurements	A reconciliation of the beginning and ending balances of recurring fair value measurements recognized in the accompanying consolidated balance sheets using significant unobservable (Level 3) inputs, except of the earnout liability for VAT Applications, is as follows (in thousands): December 31, December 31, 2018 2017 Earnout liability: Balance beginning of period $ 380 $ 6,235 Payments of earnout liability — (2,101 ) Settlement of earnout liability — (3,051 ) Total unrealized (gains) losses included in other income (380 ) (703 ) Balance end of period $ — $ 380

Balance Sheet Detail (Tables)

Balance Sheet Detail (Tables)	12 Months Ended
	Dec. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Schedule of Property and Equipment, Net	Property and equipment, net consisted of the following (in thousands): Useful December 31, December 31, Life (Years) 2018 2017 Computer equipment and software 3 $ 12,904 $ 12,884 Internally developed software 6 3,620 2,512 Furniture and fixtures 5 5,850 4,459 Office equipment 5 586 622 Leasehold improvements 1 to 10 26,788 20,339 49,748 40,816 Accumulated depreciation (16,375 ) (15,422 ) Property and equipment—net $ 33,373 $ 25,394
Schedule of Prepaid Expense And Other Current Assets	Prepaid expenses and other current assets (in thousands): December 31, December 31, 2018 2017 Prepaid expenses $ 9,578 $ 5,077 Deferred financing costs 643 1,575 Deposits 325 244 Other 761 120 Total $ 11,307 $ 7,016
Schedule of Accrued Expenses and Trade Payables	Accrued expenses and trade payables consisted of the following (in thousands): December 31, December 31, 2018 2017 Accrued payroll and related taxes $ 3,800 $ 4,155 Accrued bonus 10,766 6,280 Accrued sales commissions 6,889 2,904 ESPP contributions 6,473 - Accrued state, federal, and local taxes 1,827 1,044 Accrued referral source commissions 5,535 4,270 Trade payables 4,847 9,822 Earnout liabilities 116 3,061 Accrued leasehold improvements 424 1,288 Other 6,387 5,340 Total $ 47,064 $ 38,164

Acquisition (Tables)

Acquisition (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Schedule of Fair Values of Assets Acquired and Liabilities Assumed	The allocation of the fair value of the assets acquired and the liabilities assumed in the Gyori Purchase is provided in the following table (in thousands): Assets acquired: Current assets $ 628 Other non-current assets 65 Developed technology, customer relationships, and other intangibles 4,669 Goodwill (includes assembled workforce) 19,382 Total assets acquired 24,744 Liabilities assumed: Debt obligations, current portion 495 Other current liabilities 903 Debt obligations, non-current portion 89 Deferred tax liabilities 1,257 Other non-current liabilities 349 Total liabilities assumed 3,093 Net assets acquired $ 21,651
Summary of Valuation Methodologies, Significant Assumptions and Estimated Useful Lives	A summary of the valuation methodologies, significant assumptions, and estimated useful lives of acquired intangibles in the Gyori Purchase are provided in the below table (in thousands): Intangible Assigned Value Valuation Methodology Discount Rate Assigned Useful Life Customer relationships $ 1,073 Multi-period excess earnings-income approach 20.0 % 10 years Trademarks and trade names 81 Relief from royalty- income approach 20.0 % 1 year Developed technology and customer database 3,387 Relief from royalty- income approach 19.0 % 6 years Noncompetition agreements 128 With-and-without valuation- income approach 20.0 % 3 years

Intangible Assets (Tables)

Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Finite-lived Intangible Assets	Finite-lived intangible assets consisted of the following (in thousands) December 31, 2018 Average Useful Life (Years) Gross Accumulated Amortization Net Customer relationships 3 to 10 $ 15,412 $ (9,202 ) $ 6,210 Developed technology 3 to 8 30,935 (17,806 ) 13,129 Noncompete agreements 3 to 5 574 (542 ) 32 Tradename and trademarks 1 to 4 420 (420 ) — $ 47,341 $ (27,970 ) $ 19,371 December 31, 2017 Average Useful Life (Years) Gross Accumulated Amortization Net Customer relationships 3 to 10 $ 15,270 $ (7,347 ) $ 7,923 Developed technology 3 to 8 24,781 (13,785 ) 10,996 Noncompete agreements 3 to 5 586 (446 ) 140 Tradename and trademarks 1 to 4 419 (404 ) 15 $ 41,056 $ (21,982 ) $ 19,074
Schedule of Future Amortization Expense Related to Finite-lived Intangible Assets	Future amortization expense as of December 31, 2018, related to these finite-lived intangible assets is expected to be as follows (in thousands): Years Ending December 31 2019 $ 5,652 2020 4,607 2021 3,355 2022 2,413 2023 1,989 Thereafter 1,355 $ 19,371
Schedule of Changes in Carrying Amount of Goodwill	Changes in the carrying amount of goodwill through December 31, 2018, are summarized as follows (in thousands): Balance—January 1, 2018 $ 72,482 Cumulative translation adjustments (2,008 ) Goodwill impairment (9,174 ) Balance—December 31, 2018 $ 61,300

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Summary of Obligation for Payments under Leases	The Company’s obligation for payments under these leases is as follows (in thousands): Years Ending December 31 Operating Leases 2019 $ 9,095 2020 9,533 2021 10,048 2022 9,585 2023 8,965 Thereafter 32,729 Total minimum lease payments ( 1) $ 79,955 (1)

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of Outstanding Borrowings	Outstanding borrowings consisted of the following (in thousands): December 31, December 31, 2018 2017 Current portion: Credit facilities $ — $ 625 Note payable — 234 Total current portion of long-term debt $ — $ 859 Noncurrent portion: Credit facilities — 38,840 Total noncurrent portion of long-term debt $ — $ 38,840

Convertible Preferred Stock a_2

Convertible Preferred Stock and Shareholders' Equity (Deficit) (Tables)	12 Months Ended
	Dec. 31, 2018
Stockholders Equity Note [Abstract]
Schedule of Shares of Common Stock Reserved for Future Issuance	The following shares of common stock had been reserved for issuance upon conversion of the preferred stock, (in thousands): December 31, 2017 Conversion of outstanding Series A preferred stock 6,154 Conversion of outstanding Series A-1 preferred stock 2,344 Conversion of outstanding Series A-2 preferred stock 139 Conversion of outstanding Series B preferred stock 896 Conversion of outstanding Series B-1 preferred stock 10,759 Conversion of outstanding Series C preferred stock 3,534 Conversion of outstanding Series C-1 preferred stock 4,255 Conversion of outstanding Series D preferred stock 4,283 Conversion of outstanding Series D-1 preferred stock 11,404 Conversion of outstanding Series D-2 preferred stock 7,122 Total shares of common stock reserved for future issuance 50,890
Schedule of Series Preferred Stock Conversion Ratios and Per Share Liquidation Preference	Prior to the IPO, the Series Preferred Stock had conversion to common and liquidation values per share as follows: Preferred Stock Series Purchase Date Conversion Ratio to Common Stock Per Share Liquidation Preference A November 30, 2005 2:1 $ 0.8880 A-1 March 15, 2009 2:1 0.4440 A-2 January 21, 2010 2:1 1.6908 B May 14, 2010 2:1 0.9400 B-1 November 5, 2010 2:1 1.1000 C June 18, 2012 2:1 2.8291 C-1 November 13, 2013 2:1 1.5000 D February 12, 2014 2:1 5.2500 D-1 November 10, 2014 2:1 6.3200 D-2 September 12, 2016 2:1 6.7500
Outstanding Warrants To Purchase Stock	At December 31, 2017, the following warrants to purchase common stock were outstanding: Class Shares (In thousands) Exercise Price Fair Value at Issuance Term (Years) Common stock 490 $1.50 to $13.84 $0.178 to $6.280 10 At December 31, 2016, the following warrants to purchase common stock were outstanding: Class Shares (In Exercise Price Fair Value at Issuance Term (Years) Common stock 678 $0.96 to $12.60 $0.046 to $5.120 10

Equity Incentive Plans (Tables)

Equity Incentive Plans (Tables)	12 Months Ended
	Dec. 31, 2018
Summary of Stock-Based Compensation Expense Related to Equity Incentive Rewards	The Company recognized total stock-based compensation cost related to equity incentive awards as follows (in thousands): For the Year Ended December 31, 2018 2017 2016 Stock-based compensation cost: Common stock warrants $ 512 $ 484 $ 372 Stock options 13,279 11,295 7,767 Restricted stock units 90 - - Employee stock purchase plan 2,069 - - Total stock-based compensation cost $ 15,950 $ 11,779 $ 8,139
Summary of Stock Option Activity	The following table summarizes stock option activity for the Company’s stock-based compensation plans for 2018: Weighted Weighted Average Aggregate Average Remaining Intrinsic Exercise Contractual Value Shares Price Life (Years) (in thousands) Options outstanding as of January 1, 2018 10,727,125 $ 9.94 7.00 $ 71,430 Options granted 2,564,528 19.59 Options exercised (1,373,962 ) 7.63 Options cancelled or expired (823,621 ) 13.78 Options outstanding as of December 31, 2018 11,094,070 12.17 6.81 210,523 Options exercisable as of December 31, 2018 6,735,086 $ 9.00 5.63 $ 149,206
Summary of Options Outstanding and Vested by Range of Exercise Prices	A summary of options outstanding and vested as of December 31, 2018 is as follows: Options Outstanding Options Vested and Exercisable Number Weighted Average Number Vested Weighted Average Exercise Prices Outstanding Life (in Years) and Exercisable Life (in Years) $0.70 to $1.90 998,478 2.16 998,478 2.16 2.86 to 6.40 1,173,571 4.27 1,173,571 4.27 8.04 to 11.72 1,476,371 5.23 1,472,047 5.23 12.20 to 15.06 4,696,460 7.56 2,926,377 7.37 16.06 to 24.00 2,558,590 9.12 163,780 8.96 31.99 to 42.21 190,600 9.63 833 9.92 11,094,070 6,735,086
Summary of Fair Value Estimated Using Black-Scholes Option Pricing Model Assumptions	For the periods presented, the fair value of options was estimated using the Black-Scholes option-pricing model with the following assumptions: For the Year Ended December 31, 2018 2017 2016 Fair value of common stock $16.86 to $42.21 $13.84 to $16.06 $12.34 to $13.84 Volatility 40% 40% to 43% 40 to 45% Expected term 6 years 6 years 6 years Expected dividend yield n/a n/a n/a Risk-free interest rate 2.55% to 3.10% 2.02% to 2.22% 1.35% to 2.26%
Summary of RSU Activity	The following table summarizes RSU activity for the Company’s stock-based compensation plans for 2018: Weighted Average Grant Date Fair Shares Value Per Share RSUs outstanding as of January 1, 2018 — $ — RSUs granted 74,757 32.69 RSUs vested — — RSUs cancelled (333 ) 33.52 RSUs outstanding as of December 31, 2018 74,424 $ 32.69
2018 Employee Stock Purchase Plan
Summary of Fair Value Estimated Using Black-Scholes Option Pricing Model Assumptions	For 2018, the fair value of ESPP purchase rights was estimated using the Black-Scholes option-pricing model with the following assumptions: December 31, 2018 Fair value of common stock $24.00 to $38.18 Volatility 40% Expected term 0.5 years Expected dividend yield n/a Risk-free interest rate 2.90% to 2.96%

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Domestic and Foreign Components of Loss Before Income Tax	Domestic and foreign components of loss before income tax are as follows (in thousands): December 31, 2018 2017 2016 Domestic $ (48,949 ) $ (41,575 ) $ (54,743 ) Foreign (27,577 ) (23,770 ) (2,505 ) Total $ (76,526 ) $ (65,345 ) $ (57,248 )
Schedule of Components of the Income Tax Provision ( Benefit)	Major components of the income tax provision (benefit) are as follows (in thousands): December 31, 2018 2017 2016 Current: Federal $ — $ — $ — State — — — Foreign 317 87 552 Total current income tax provision 317 87 552 Deferred: Federal (825 ) (368 ) 435 State 64 90 38 Foreign (532 ) (1,028 ) (385 ) Total deferred income tax provision (1,293 ) (1,306 ) 88 Total $ (976 ) $ (1,219 ) $ 640
Schedule of Major Differences Between U.S Statutory Rate and Effective Tax Rate	Major differences between the U.S. statutory rate (21% for 2018 and 35% for 2017 and 2016) and the effective tax rate are as follows (in thousands): December 31, 2018 2017 2016 Tax at statutory rate $ (16,071 ) $ (22,871 ) $ (20,156 ) State taxes (3,375 ) (2,531 ) (1,863 ) Research and development credits (471 ) (1,460 ) (793 ) Changes in tax law — (840 ) — Stock-based compensation (3,246 ) (3,110 ) 85 Goodwill impairment 3,119 2,903 — Foreign rate differential (2,488 ) 1,815 748 Change in valuation allowance 20,006 21,644 22,118 Intercompany intangible asset sale 1,811 — — Other (261 ) 3,231 501 Total $ (976 ) $ (1,219 ) $ 640
Schedule of Significant Components of Deferred Tax Assets and Liabilities	Significant components of the Company’s deferred tax assets and liabilities are as follows (in thousands): December 31, 2018 2017 Deferred tax assets: Net operating loss carryforward $ 91,529 $ 74,215 Share-based compensation 8,219 6,622 Deferred revenue 2,186 2,748 Research and development credit, net of uncertain tax position reserve 4,182 3,586 Other 7,134 2,672 Total deferred tax assets 113,250 89,843 Deferred tax liabilities: Definite lived intangibles (590 ) (2,137 ) Other (5,368 ) (1,714 ) Total deferred tax liabilities (5,958 ) (3,851 ) Net deferred tax assets before valuation allowance 107,292 85,992 Valuation allowance (107,852 ) (87,846 ) Net deferred tax liability $ (560 ) $ (1,854 )
Schedule of Reconciliation of Unrecognized Tax Benefits	A reconciliation of the beginning and ending balances for unrecognized tax benefits is as follows (in thousands): December 31, 2018 2017 2016 Balance at January 1 $ 3,300 $ 2,727 $ 3,796 Additions for tax positions related to the current year 1,446 867 242 Additions for tax positions related to prior years — — — Reductions for tax positions related to prior years (628 ) (294 ) (1,311 ) Reductions related to settlements — — — Reductions related to a lapse of statute — — — Balance at December 31 $ 4,118 $ 3,300 $ 2,727

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable to Common Shareholders (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Net Loss Per Common Share	The following table sets forth the computation of basic and diluted net loss per common share (in thousands, except per share amounts): Year Ended December 31, 2018 2017 2016 Numerator: Net loss attributable to common shareholders $ (75,550 ) $ (64,126 ) $ (57,888 ) Denominator: Weighted-average common shares outstanding-basic 38,692 5,632 5,706 Dilutive effect of share equivalents resulting from stock options, common stock warrants and convertible preferred shares (as converted) — — — Weighted-average common shares outstanding-diluted 38,692 5,632 5,706 Net loss per common share, basic and diluted $ (1.95 ) $ (11.39 ) $ (10.15 )
Schedule of Potential Shares Not Included in the Computation of Diluted Earnings Per Share	The following weighted-average outstanding shares of common stock equivalents were excluded from the computation of diluted net loss per share attributable to common shareholders for the periods presented because the impact of including them would have been antidilutive (in thousands): Year Ended December 31, 2018 2017 2016 Options to purchase common shares 11,271 10,507 8,653 Unvested restricted stock units 9 — — Employee stock purchase plan shares 71 — — Common stock warrants 236 580 679 Convertible preferred shares (as converted) 23,562 50,893 47,185 Preferred stock warrants — — 26 Total 35,149 61,980 56,543

Significant Accounting Polici_4

Significant Accounting Policies - Additional Information (Details)	Oct. 31, 2018USD ($)	May 10, 2018	Jan. 01, 2017USD ($)	Jun. 30, 2018USD ($)$ / sharesshares	Dec. 31, 2018USD ($)Segment$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2015USD ($)shares
Accounting Policies [Line Items]
Proceeds from initial public offering, net of underwriting discounts					$ 192,510,000
Offering expenses paid and payable					$ 3,425,000
Reverse stock split		0.5
Common stock, shares, outstanding | shares					66,769,000	5,992,000
Number of operating segment | Segment					1
Net loss					$ (75,550,000)	$ (64,126,000)	$ (57,888,000)
Accumulated deficit					(487,602,000)	(412,052,000)
Cash and cash equivalents					142,322,000	14,075,000	20,230,000	$ 10,677,000
Funds held from customers					13,113,000	13,082,000
Capitalized software development Costs					1,100,000	1,000,000	800,000
Goodwill impairment	$ 0				9,174,000	8,418,000	0
Other income (expense), net					400,000	700,000	(300,000)
Impairment of long-lived assets						0	0
Impairment of long-lived assets other than goodwill					$ 0
Tax position likely of being realized upon ultimate settlement					greater than 50%
Percentage of likelihood of realization of tax position upon ultimate settlement, minimum					50.00%
Expected customer relationship term					6 years
Interest income earned on funds held for customers					$ 1,100,000
Partner commissions					21,700,000	14,300,000	9,900,000
Advertising expenses					18,800,000	22,700,000	19,600,000
Contribution to 401(k) plan					800,000	700,000	600,000
Deferred financing costs					643,000	1,575,000
Restructuring charges						800,000
Restructuring charges					0	752,000	$ 0
Restructuring liability remained					$ 0	600,000
Accounting Standards Update 2016-09
Accounting Policies [Line Items]
Change in Valuation Allowance			$ 11,300,000
Employee Severance
Accounting Policies [Line Items]
Restructuring charges						700,000
Impairments Loss on Fixed Assets
Accounting Policies [Line Items]
Impairment loss on fixed assets						$ 100,000
Customer Relationships
Accounting Policies [Line Items]
Expected customer relationship term					6 years
Internally Developed Software
Accounting Policies [Line Items]
Property and equipment, Useful Life					6 years
Maximum
Accounting Policies [Line Items]
Common stock price per share | $ / shares					$ 42.21	$ 16.06	$ 13.84
Maximum | ASU 2014-09
Accounting Policies [Line Items]
Reduction of deferred revenue					$ 15,000,000
Additional contract costs to be capitalized					$ 22,000,000
Minimum
Accounting Policies [Line Items]
Common stock price per share | $ / shares					$ 16.86	$ 13.84	$ 12.34
Minimum | ASU 2014-09
Accounting Policies [Line Items]
Reduction of deferred revenue					$ 11,000,000
Additional contract costs to be capitalized					$ 18,000,000
Geographic Concentration Risk | Non-US | Revenue
Accounting Policies [Line Items]
Concentration risk					6.00%	5.00%	3.00%
Geographic Concentration Risk | Non-US | Long-lived Assets
Accounting Policies [Line Items]
Concentration risk					7.00%	11.00%
Geographic Concentration Risk | United Kingdom | Long-lived Assets
Accounting Policies [Line Items]
Concentration risk					3.00%	5.00%
Customer Concentration Risk | Revenue | Maximum
Accounting Policies [Line Items]
Concentration risk					10.00%	10.00%
Customer Concentration Risk | Accounts Receivable | Maximum
Accounting Policies [Line Items]
Concentration risk					10.00%	10.00%
Common Stock
Accounting Policies [Line Items]
Initial public offering | shares					8,625,000
Preferred stock, conversion basis		2-to-1			2-to-1
Reverse stock split		0.5		0.5
Common stock, shares, outstanding | shares					66,768,563	5,992,293	5,297,833	5,643,959
Common Stock | Initial Public Offering
Accounting Policies [Line Items]
Initial public offering | shares				8,625,000
Common stock price per share | $ / shares				$ 24
Proceeds from initial public offering, net of underwriting discounts				$ 192,500,000
Offering expenses paid and payable				$ 3,400,000
Common Stock | Underwriters
Accounting Policies [Line Items]
Initial public offering | shares				1,125,000
Additional Paid-In Capital
Accounting Policies [Line Items]
Offering expenses paid and payable					$ 3,425,000
Reduction of deferred revenue						$ 110,000
Additional Paid-In Capital | Accounting Standards Update 2016-09
Accounting Policies [Line Items]
Net cumulative-effect of adopting new accounting standard						100,000
Accumulated Deficit
Accounting Policies [Line Items]
Net loss					$ (75,550,000)	(64,126,000)	$ (57,888,000)
Reduction of deferred revenue						(110,000)
Accumulated Deficit | Accounting Standards Update 2016-09
Accounting Policies [Line Items]
Net cumulative-effect of adopting new accounting standard			$ 11,300,000			$ 100,000

Significant Accounting Polici_5

Significant Accounting Policies - Allowance For Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for Doubtful Accounts [Roll Forward]
Balance at the beginning of the year	$ 666
Balance at the beginning of the year	905
Balance at the end of the year	198	$ 666
Balance at the end of the year	521	905
Receivables From Customers
Allowance for Doubtful Accounts [Roll Forward]
Balance at the beginning of the year	666	754	$ 266
Charged to expense	(83)	(88)	517
Write-offs	(385)		(29)
Balance at the end of the year	198	666	754
Trade Accounts Receivable
Allowance for Doubtful Accounts [Roll Forward]
Balance at the beginning of the year	905	1,324	1,154
Charged to expense	(183)	(105)	2,390
Write-offs	(201)	(314)	(2,220)
Balance at the end of the year	$ 521	$ 905	$ 1,324

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Recurring Basis - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Earnout Related to Acquisitions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value, Liabilities		$ 380
Significant Unobservable Inputs (Level 3) | Earnout Related to Acquisitions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value, Liabilities		380
Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value, Assets	$ 138,483	10,261
Money Market Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value, Assets	$ 138,483	$ 10,261

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) $ in Thousands, € in Millions	Oct. 31, 2018USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2017EUR (€)	Dec. 31, 2016USD ($)	Sep. 22, 2016	Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Earnout liability		$ 0			$ 663
Goodwill		61,300	$ 72,482
Goodwill impairment	$ 0	9,174	8,418		$ 0
Brazilian Segment
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Goodwill		9,200	19,800
Goodwill fair value		0	11,400
Goodwill impairment		$ 9,200	8,400
Recurring Basis | Significant Unobservable Inputs (Level 3) | Current Liabilities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Settlement of earnout liability for VAT applications			$ 3,100	€ 2.5
Discount Rate | Discounted Cash Flow and Monte Carlo Simulations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rate utilized for valuation of earnout liability					16.00%		15.00%
Discount Rate | Discounted Cash Flow and Monte Carlo Simulations | Gyori
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rate utilized for valuation of earnout liability			22.00%		20.00%	19.00%

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Reconciliation of Beginning and Ending Balances of Recurring Fair Value Measurements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnout liability:
Total unrealized (gains) losses included in other income	$ (400)	$ (700)	$ 300
Recurring Basis | Significant Unobservable Inputs (Level 3) | Earnout Related to Acquisitions
Earnout liability:
Balance beginning of period	380	6,235
Payments of earnout liability		(2,101)
Settlement of earnout liability		(3,051)
Total unrealized (gains) losses included in other income	$ (380)	(703)
Balance end of period		$ 380	$ 6,235

Balance Sheet Detail - Property

Balance Sheet Detail - Property and Equipment, Net (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 49,748	$ 40,816
Accumulated depreciation	(16,375)	(15,422)
Property and equipment—net	33,373	25,394
Computer Equipment and Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 12,904	12,884
Property and equipment, Useful Life	3 years
Internally Developed Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 3,620	2,512
Property and equipment, Useful Life	6 years
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 5,850	4,459
Property and equipment, Useful Life	5 years
Office Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 586	622
Property and equipment, Useful Life	5 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 26,788	$ 20,339
Leasehold Improvements | Minimum
Property Plant And Equipment [Line Items]
Property and equipment, Useful Life	1 year
Leasehold Improvements | Maximum
Property Plant And Equipment [Line Items]
Property and equipment, Useful Life	10 years

Balance Sheet Detail - Addition

Balance Sheet Detail - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Balance Sheet Related Disclosures [Abstract]
Depreciation expense	$ 6.8	$ 4.9	$ 5.2

Balance Sheet Detail - Prepaid

Balance Sheet Detail - Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Prepaid Expense And Other Assets Current [Abstract]
Prepaid expenses	$ 9,578	$ 5,077
Deferred financing costs	643	1,575
Deposits	325	244
Other	761	120
Total	$ 11,307	$ 7,016

Balance Sheet Detail - Accrued

Balance Sheet Detail - Accrued Expenses and Trade Payables (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accounts Payable And Accrued Liabilities Current [Abstract]
Accrued payroll and related taxes	$ 3,800	$ 4,155
Accrued bonus	10,766	6,280
Accrued sales commissions	6,889	2,904
ESPP contributions	6,473	0
Accrued state, federal, and local taxes	1,827	1,044
Accrued referral source commissions	5,535	4,270
Trade payables	4,847	9,822
Earnout liabilities	116	3,061
Accrued leasehold improvements	424	1,288
Other	6,387	5,340
Total	$ 47,064	$ 38,164

Acquisition - Additional Inform

Acquisition - Additional Information (Details) - USD ($)	Oct. 31, 2018	Sep. 22, 2016	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016	Oct. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Accrued value of earnout related to acquisition					$ 663,000		$ 0		$ 663,000
Goodwill				$ 72,482,000			61,300,000	$ 72,482,000
Goodwill impairment	$ 0						9,174,000	8,418,000	0
Revenue							272,098,000	213,159,000	167,426,000
Loss before income taxes							$ (76,526,000)	$ (65,345,000)	(57,248,000)
Proforma revenue									172,000,000
Proforma net loss									(59,700,000)
BRAZIL
Business Acquisition [Line Items]
Goodwill impairment			$ 9,200,000			$ 8,400,000
Gyori | BRAZIL
Business Acquisition [Line Items]
Acquisition-related costs									$ 1,200,000
Total purchase price		$ 21,700,000
Consideration in cash		17,200,000
Accrued value of earnout related to acquisition		700,000
Maximum Annual Payout Earned		$ 6,800,000
Payout period		3 years
Goodwill		$ 19,382,000
Goodwill impairment			$ 9,200,000	$ 8,400,000
Revenue					1,200,000
Loss before income taxes					$ (1,400,000)
Gyori | BRAZIL | July 1, 2016 to June 30, 2017
Business Acquisition [Line Items]
Maximum Annual Payout Earned		$ 600,000
Growth rate		25.00%
Payout earned		$ 0
Gyori | BRAZIL | July 1, 2017 to June 30, 2018
Business Acquisition [Line Items]
Maximum Annual Payout Earned		$ 2,500,000
Growth rate		68.75%
Payout earned		$ 0
Gyori | BRAZIL | July 1, 2018 to June 30, 2019
Business Acquisition [Line Items]
Maximum Annual Payout Earned		$ 3,700,000
Growth rate		144.69%
Gyori | BRAZIL | Common Stock
Business Acquisition [Line Items]
Stock issued ,shares		285,710
Stock issued ,value		$ 3,800,000

Acquisition - Schedule of Fair

Acquisition - Schedule of Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Sep. 22, 2016
Assets acquired:
Goodwill	$ 61,300	$ 72,482
Gyori | BRAZIL
Assets acquired:
Current assets			$ 628
Other non-current assets			65
Developed technology, customer relationships, and other intangibles			4,669
Goodwill			19,382
Total assets acquired			24,744
Liabilities assumed:
Debt obligations, current portion			495
Other current liabilities			903
Debt obligations, non-current portion			89
Deferred tax liabilities			1,257
Other non-current liabilities			349
Total liabilities assumed			3,093
Net assets acquired			$ 21,651

Acquisition - Summary Of The Va

Acquisition - Summary Of The Valuation Methodologies Significant Assumptions, And Estimated Useful Lives Of Acquired Intangibles (Details) - Gyori - BRAZIL $ in Thousands	Sep. 22, 2016USD ($)
Business Acquisition [Line Items]
Intangible assets Assigned value	$ 4,669
Customer Relationships
Business Acquisition [Line Items]
Intangible assets Assigned value	$ 1,073
Valuation Methodology	Multi-period excess earnings-income approach
Discount Rate	20.00%
Intangible asset, useful life	10 years
Tradename and Trademarks
Business Acquisition [Line Items]
Intangible assets Assigned value	$ 81
Valuation Methodology	Relief from royalty- income approach
Discount Rate	20.00%
Intangible asset, useful life	1 year
Developed Technology
Business Acquisition [Line Items]
Intangible assets Assigned value	$ 3,387
Valuation Methodology	Relief from royalty- income approach
Discount Rate	19.00%
Intangible asset, useful life	6 years
Noncompete Agreements
Business Acquisition [Line Items]
Intangible assets Assigned value	$ 128
Valuation Methodology	With-and-without valuation- income approach
Discount Rate	20.00%
Intangible asset, useful life	3 years

Intangible Assets - Schedule of

Intangible Assets - Schedule of Finite-lived Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Finite Lived Intangible Assets [Line Items]
Gross	$ 47,341	$ 41,056
Accumulated Amortization	(27,970)	(21,982)
Net	19,371	19,074
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Gross	15,412	15,270
Accumulated Amortization	(9,202)	(7,347)
Net	$ 6,210	$ 7,923
Customer Relationships | Minimum
Finite Lived Intangible Assets [Line Items]
Average Useful Life (Years)	3 years	3 years
Customer Relationships | Maximum
Finite Lived Intangible Assets [Line Items]
Average Useful Life (Years)	10 years	10 years
Developed Technology
Finite Lived Intangible Assets [Line Items]
Gross	$ 30,935	$ 24,781
Accumulated Amortization	(17,806)	(13,785)
Net	$ 13,129	$ 10,996
Developed Technology | Minimum
Finite Lived Intangible Assets [Line Items]
Average Useful Life (Years)	3 years	3 years
Developed Technology | Maximum
Finite Lived Intangible Assets [Line Items]
Average Useful Life (Years)	8 years	8 years
Noncompete Agreements
Finite Lived Intangible Assets [Line Items]
Gross	$ 574	$ 586
Accumulated Amortization	(542)	(446)
Net	$ 32	$ 140
Noncompete Agreements | Minimum
Finite Lived Intangible Assets [Line Items]
Average Useful Life (Years)	3 years	3 years
Noncompete Agreements | Maximum
Finite Lived Intangible Assets [Line Items]
Average Useful Life (Years)	5 years	5 years
Tradename and Trademarks
Finite Lived Intangible Assets [Line Items]
Gross	$ 420	$ 419
Accumulated Amortization	$ (420)	(404)
Net		$ 15
Tradename and Trademarks | Minimum
Finite Lived Intangible Assets [Line Items]
Average Useful Life (Years)	1 year	1 year
Tradename and Trademarks | Maximum
Finite Lived Intangible Assets [Line Items]
Average Useful Life (Years)	4 years	4 years

Intangible Assets - Additional

Intangible Assets - Additional Information (Details)

Nov. 29, 2019shares

May 29, 2019shares

Nov. 29, 2018shares

Oct. 31, 2018USD ($)

Jun. 30, 2018USD ($)

May 31, 2018USD ($)shares

Jun. 30, 2018USD ($)

Sep. 30, 2018USD ($)

Oct. 31, 2017USD ($)

Dec. 31, 2018USD ($)Unit

Dec. 31, 2017USD ($)

Dec. 31, 2016USD ($)

Finite Lived Intangible Assets [Line Items]

Finite-lived intangible assets, amortization expense

$ 6,000,000

$ 5,700,000

$ 5,100,000

Cash payment to sellers

5,002,000

Earnout liabilitiy

116,000

3,061,000

Goodwill impairment charge

$ 0

$ 9,174,000

8,418,000

$ 0

Number of goodwill impairment reporting units | Unit

3

Weighted average cost of capital risk adjusted percentage

30.00%

Accumulated goodwill impairment

$ 17,600,000

8,400,000

Goodwill

$ 61,300,000

$ 72,482,000

European Reporting Unit

Finite Lived Intangible Assets [Line Items]

Weighted average cost of capital

25.00%

Brazilian Reporting Unit

Finite Lived Intangible Assets [Line Items]

Goodwill

$ 0

BRAZIL

Finite Lived Intangible Assets [Line Items]

Goodwill impairment charge

$ 9,200,000

$ 8,400,000

Accrued Expenses and Trade Payables

Finite Lived Intangible Assets [Line Items]

Earnout liabilitiy

$ 100,000

Atlantax Systems, Inc

Finite Lived Intangible Assets [Line Items]

Prepayment funded for future earnings

$ 400,000

Tradestream Technologies Inc. and Wise 24 Inc

Finite Lived Intangible Assets [Line Items]

Future revenue recognized period

6 years

Cash payment to sellers

$ 2,500,000

$ 1,500,000

$ 4,000,000

Common stock Issue | shares

37,708

113,122

Legal costs related to transaction

$ 100,000

Tradestream Technologies Inc. and Wise 24 Inc | Scenario, Forecast

Finite Lived Intangible Assets [Line Items]

Common stock Issue | shares

37,706

37,708

Tradestream Technologies Inc. and Wise 24 Inc | Maximum

Finite Lived Intangible Assets [Line Items]

Total consideration price

$ 30,000,000

Customer Relationships | Maximum

Finite Lived Intangible Assets [Line Items]

Intangible asset, useful life

10 years

10 years

Customer Relationships | Minimum

Finite Lived Intangible Assets [Line Items]

Intangible asset, useful life

3 years

3 years

Customer Relationships | Atlantax Systems, Inc

Finite Lived Intangible Assets [Line Items]

Future revenue recognized period

4 years

Prepayment for acquisition of intangible assets

$ 400,000

Intangible asset, useful life

5 years

Customer Relationships | Atlantax Systems, Inc | Maximum

Finite Lived Intangible Assets [Line Items]

Total consideration price

$ 1,900,000

Developed Technology | Maximum

Finite Lived Intangible Assets [Line Items]

Intangible asset, useful life

8 years

8 years

Developed Technology | Minimum

Finite Lived Intangible Assets [Line Items]

Intangible asset, useful life

3 years

3 years

Developed Technology | Tradestream Technologies Inc. and Wise 24 Inc

Finite Lived Intangible Assets [Line Items]

Total consideration price

$ 6,600,000

Intangible asset, useful life

6 years

Total consideration consisting of cash paid

$ 7,100,000

Current other receivable

$ 500,000

Intangible Assets - Schedule _2

Intangible Assets - Schedule of Future Amortization Expense Related to Finite-lived Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets, Net [Abstract]
2,019	$ 5,652
2,020	4,607
2,021	3,355
2,022	2,413
2,023	1,989
Thereafter	1,355
Net	$ 19,371	$ 19,074

Intangible Assets - Schedule _3

Intangible Assets - Schedule of Changes in Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	Oct. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Balance—January 1, 2018		$ 72,482
Cumulative translation adjustments		(2,008)
Goodwill impairment	$ 0	(9,174)	$ (8,418)	$ 0
Balance—December 31, 2018		$ 61,300	$ 72,482

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loss Contingencies [Line Items]
Rent expense		$ 9,900,000	$ 5,700,000	$ 4,800,000
Sublease income	$ 300,000
Lease expiration period	2,022
Loss contingency, inestimable loss		The Company has not recorded an accrual related to these arrangements as of December 31, 2018 or 2017 because it has not determined that a loss is probable.
Maximum
Loss Contingencies [Line Items]
Estimated range of loss	$ 2,000,000	$ 2,000,000	2,000,000
Sales Tax Audit
Loss Contingencies [Line Items]
Reserve For losses from tax	100,000	100,000	$ 100,000
Network Infrastructure, Hosting Services and Software Licenses
Loss Contingencies [Line Items]
Purchase obligation due, 2019	4,400,000	4,400,000
Purchase obligation due, 2020	3,500,000	3,500,000
Purchase obligation due, 2021	$ 3,500,000	3,500,000
King Street Lease
Loss Contingencies [Line Items]
Base rent for first year		231,424
Base rent for final year		$ 578,872

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Obligation for Payments under Leases (Details) $ in Thousands	Dec. 31, 2018USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2,019	$ 9,095
2,020	9,533
2,021	10,048
2,022	9,585
2,023	8,965
Thereafter	32,729
Total minimum lease payments	$ 79,955

Commitments and Contingencies_3

Commitments and Contingencies - Sumary of Obligation for Payments under Leases (Parenthetical) (Details) $ in Millions	Dec. 31, 2018USD ($)
Commitments And Contingencies Disclosure [Abstract]
Minimum sublease rentals	$ 5.4

Debt - Additional Information (

Debt - Additional Information (Details) - USD ($)	1 Months Ended			3 Months Ended	12 Months Ended
	Aug. 31, 2018	Jun. 30, 2018	Nov. 30, 2017	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Aug. 31, 2008
Line Of Credit Facility [Line Items]
Repayments of revolving credit facility					$ 63,000,000	$ 2,935,000	$ 52,000,000
Note payable						234,000		$ 400,000
Note payable annual interest rate								2.54%
Deferred financing fees, net of amortization			$ 400,000
Loan and Security Agreement
Line Of Credit Facility [Line Items]
Deferred financing fees, net of amortization					200,000	$ 500,000
Deferred financing fees net of amortization, written off				$ 100,000
Term Loan | Loan and Security Agreement | Silicon Valley Bank and Ally Bank
Line Of Credit Facility [Line Items]
Credit facilities amount			$ 30,000,000
Repayments of credit facility	$ 30,000,000
Credit facilities, repayment month and year			2018-08
Revolving Credit Facility | Loan and Security Agreement | Silicon Valley Bank and Ally Bank
Line Of Credit Facility [Line Items]
Credit facilities amount			$ 50,000,000
Credit facilities, repayment month and year			2019-11
Repayments of revolving credit facility		$ 33,000,000
Borrowings outstanding					$ 0
Quarterly fee on undrawn portion available under credit facilities			0.50%
Revolving Credit Facility | Loan and Security Agreement | Silicon Valley Bank and Ally Bank | Maximum
Line Of Credit Facility [Line Items]
Credit facilities, interest rate			4.25%
Revolving Credit Facility | Loan and Security Agreement | Silicon Valley Bank and Ally Bank | Prime Rate | Maximum
Line Of Credit Facility [Line Items]
Credit facilities, variable rate			1.75%

Debt - Schedule of Outstanding

Debt - Schedule of Outstanding Borrowings (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Aug. 31, 2008
Current portion:
Credit facilities	$ 625
Note payable	234	$ 400
Total current portion of long-term debt	859
Noncurrent portion:
Credit facilities	38,840
Total noncurrent portion of long-term debt	$ 38,840

Convertible Preferred Stock a_3

Convertible Preferred Stock and Shareholders' Equity (Deficit) - Additional Information (Details)	Jun. 14, 2018USD ($)$ / sharesshares	May 10, 2018	Dec. 31, 2018USD ($)Class$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares
Class Of Stock [Line Items]
Number of classes of stock | Class			2
Capital stock, authorized shares	260,290,986		620,000,000
Common stock, shares authorized	153,944,895		600,000,000	153,945,000
Common stock, par value | $ / shares	$ 0.0001		$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	106,346,091		0	106,346,091
Convertible preferred stock, par value | $ / shares	$ 0.0001			$ 0.0001
Preferred stock, shares authorized			20,000,000	0
Preferred stock, par value | $ / shares			$ 0.0001	$ 0.0001
Description of IPO transaction			There were no changes to the rights and preferences of the common stock as a result of the IPO.
Fair value of shares repurchased | $			$ 1,738,000		$ 36,022,000
Preferred stock converted into common stock	50,888,014
Convertible preferred stock, shares issued			0
Convertible preferred stock, shares outstanding			0
Dividend Payable | $			$ 0	$ 0	0
Stock-based compensation cost | $			$ 15,950,000	$ 11,779,000	$ 8,139,000
Common Stock
Class Of Stock [Line Items]
Preferred stock, conversion basis		2-to-1	2-to-1
Number of warrants net exercised to common stock			144,945
Common Stock Warrants
Class Of Stock [Line Items]
Number of warrants outstanding			0
Number of warrants exercised	363,000
Proceeds from exercise of warrants | $	$ 3,700,000
Employees And Non Employee Investors [Member]
Class Of Stock [Line Items]
Fair value of shares repurchased | $			$ 1,700,000
Board of Directors | Common Stock Warrants
Class Of Stock [Line Items]
Number of common stock warrants issued			80,000	80,000	80,000
Common stock warrants, weighted average exercise price, per share | $ / shares			$ 16.60	$ 13.84	$ 12.60
Board of Directors | Common Stock Warrants | General and Administrative
Class Of Stock [Line Items]
Stock-based compensation cost | $			$ 500,000	$ 500,000	$ 400,000

Convertible Preferred Stock a_4

Convertible Preferred Stock and Shareholder's Equity (Deficit) - Schedule of Shares of Common Stock Reserved for Future Issuance (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2017shares
Shares of common stock reserved for future issuance [Line Items]
Total shares of common stock reserved for future issuance	50,890
Series A Preferred Stock
Shares of common stock reserved for future issuance [Line Items]
Conversion of outstanding preferred stock	6,154
Series A 1 Preferred Stock
Shares of common stock reserved for future issuance [Line Items]
Conversion of outstanding preferred stock	2,344
Series A 2 Preferred Stock
Shares of common stock reserved for future issuance [Line Items]
Conversion of outstanding preferred stock	139
Series B Preferred Stock
Shares of common stock reserved for future issuance [Line Items]
Conversion of outstanding preferred stock	896
Series B 1 Preferred Stock
Shares of common stock reserved for future issuance [Line Items]
Conversion of outstanding preferred stock	10,759
Series C Preferred Stock
Shares of common stock reserved for future issuance [Line Items]
Conversion of outstanding preferred stock	3,534
Series C 1 Preferred Stock
Shares of common stock reserved for future issuance [Line Items]
Conversion of outstanding preferred stock	4,255
Series D Preferred Stock
Shares of common stock reserved for future issuance [Line Items]
Conversion of outstanding preferred stock	4,283
Series D-1 Preferred Stock
Shares of common stock reserved for future issuance [Line Items]
Conversion of outstanding preferred stock	11,404
Series D-2 Preferred Stock
Shares of common stock reserved for future issuance [Line Items]
Conversion of outstanding preferred stock	7,122

Convertible Preferred Stock a_5

Convertible Preferred Stock and Shareholder's Equity (Deficit) - Schedule of Series Preferred Stock Conversion Ratios and Per Share Liquidation Preference (Details)	12 Months Ended
	Dec. 31, 2018$ / shares
Series A Preferred Stock
Class Of Stock [Line Items]
Purchase Date	Nov. 30, 2005
Conversion Ratio to Common Stock	2-to-1
Per Share Liquidation Preference	$ 0.8880
Series A 1 Preferred Stock
Class Of Stock [Line Items]
Purchase Date	Mar. 15, 2009
Conversion Ratio to Common Stock	2-to-1
Per Share Liquidation Preference	$ 0.4440
Series A 2 Preferred Stock
Class Of Stock [Line Items]
Purchase Date	Jan. 21, 2010
Conversion Ratio to Common Stock	2-to-1
Per Share Liquidation Preference	$ 1.6908
Series B Preferred Stock
Class Of Stock [Line Items]
Purchase Date	May 14, 2010
Conversion Ratio to Common Stock	2-to-1
Per Share Liquidation Preference	$ 0.9400
Series B 1 Preferred Stock
Class Of Stock [Line Items]
Purchase Date	Nov. 5, 2010
Conversion Ratio to Common Stock	2-to-1
Per Share Liquidation Preference	$ 1.1000
Series C Preferred Stock
Class Of Stock [Line Items]
Purchase Date	Jun. 18, 2012
Conversion Ratio to Common Stock	2-to-1
Per Share Liquidation Preference	$ 2.8291
Series C 1 Preferred Stock
Class Of Stock [Line Items]
Purchase Date	Nov. 13, 2013
Conversion Ratio to Common Stock	2-to-1
Per Share Liquidation Preference	$ 1.5000
Series D Preferred Stock
Class Of Stock [Line Items]
Purchase Date	Feb. 12, 2014
Conversion Ratio to Common Stock	2-to-1
Per Share Liquidation Preference	$ 5.2500
Series D-1 Preferred Stock
Class Of Stock [Line Items]
Purchase Date	Nov. 10, 2014
Conversion Ratio to Common Stock	2-to-1
Per Share Liquidation Preference	$ 6.3200
Series D-2 Preferred Stock
Class Of Stock [Line Items]
Purchase Date	Sep. 12, 2016
Conversion Ratio to Common Stock	2-to-1
Per Share Liquidation Preference	$ 6.7500

Convertible Preferred Stock a_6

Convertible Preferred Stock and Shareholder's Equity (Deficit) - Schedule of Outstanding Warrants to Purchase Common Stock (Details) - Common Stock - USD ($) $ / shares in Units, shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Class Of Stock [Line Items]
Shares (In thousands)	490	678
Term (Years)	10 years	10 years
Minimum
Class Of Stock [Line Items]
Exercise Price	$ 1.50	$ 0.96
Fair Value at Issuance	$ 0.178	$ 0.046
Maximum
Class Of Stock [Line Items]
Exercise Price	$ 13.84	$ 12.60
Fair Value at Issuance	$ 6.280	$ 5.120

Equity Incentive Plans - Additi

Equity Incentive Plans - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jul. 14, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock reserved for issuance		50,890,000
Shares subject to outstanding awards	11,094,070	10,727,125
Total intrinsic value of options exercised	$ 17.4	$ 6.6	$ 8.6
Weighted average grant date fair value of options granted	$ 9.07	$ 6.44	$ 5.76
Number of shares, vested	2,002,503
Number of options unvested	4,358,984
Contractual life	10 years
Stock options, average vesting term	4 years
Expected term	6 years	6 years	6 years
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total unrecognized compensation expense related to stock options	$ 27.6
Unrecognized compensation expense expected to be recognized over period	3 years
Stock options vesting period	4 years
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense expected to be recognized over period	4 years
Total unrecognized compensation expense expected to be recognized	$ 2.3
2018 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock reserved for issuance	5,315,780
Automatically increase percentage of aggregate number of shares of common stock outstanding	5.00%
Shares subject to outstanding awards	265,024
Shares available for future issuance	5,197,276
2006 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares subject to outstanding awards	10,889,879
Shares available for future issuance				0
Taxcient Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares subject to outstanding awards	13,591
2018 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock reserved for issuance	996,709
Total unrecognized compensation expense related to stock options	$ 0.3
Contractual life	10 years
Expected term	6 months
Initial offering period	June 15, 2018
Description of offering period for ESPP	The first offering period began on June 15, 2018 and ended on January 31, 2019. Future offering periods will begin on August 1 and February 1 (or such other date determined by the Company’s Board of Directors or Compensation and Leadership Development Committee).
Minimum weekly hours required to work for getting eligible to participate in ESPP	20 hours
Description of purchase price for shares of common stock purchased under ESPP	The purchase price for shares of common stock purchased under the ESPP is 85% of the lesser of the fair market value of the Company’s common stock on (i) the first day of the applicable offering period or (ii) the last day of the purchase period in the applicable offering period.
Percentage of purchase price for shares of common stock under fair value market	85.00%
Employee stock purchase plan number of shares initially authorized	10,102,525
2018 Employee Stock Purchase Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Automatically increase percentage of aggregate number of shares of common stock outstanding	1.00%
Percentage of payroll deduction on eligible compensation	1.00%
Increase of common stock capital shares reserved for future issuance in each of calendar year	1,000,000
2018 Employee Stock Purchase Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of payroll deduction on eligible compensation	15.00%

Equity Incentive Plans - Summar

Equity Incentive Plans - Summary of Stock-Based Compensation Expense Related to Equity Incentive Rewards (Details) - USD ($) $ 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-based compensation cost	$ 15,950	$ 11,779	$ 8,139
Common Stock Warrants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation cost	512	484	372
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation cost	13,279	$ 11,295	$ 7,767
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation cost	90
Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation cost	$ 2,069

Equity Incentive Plans - Summ_2

Equity Incentive Plans - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Shares
Options outstanding beginning balance	10,727,125
Options granted	2,564,528
Options exercised	(1,373,962)
Options cancelled or expired	(823,621)
Options outstanding ending balance	11,094,070	10,727,125
Options exercisable	6,735,086
Weighted Average Exercise Price
Options outstanding beginning balance	$ 9.94
Options granted	19.59
Options exercised	7.63
Options cancelled or expired	13.78
Options outstanding ending balance	12.17	$ 9.94
Options exercisable	$ 9
Weighted Average Remaining Contractual Life (Years)
Options outstanding	6 years 9 months 21 days	7 years
Options exercisable	5 years 7 months 17 days
Aggregate Intrinsic Value
Options outstanding	$ 210,523	$ 71,430
Options exercisable	$ 149,206

Equity Incentive Plans - Summ_3

Equity Incentive Plans - Summary of Options Outstanding and Vested (Details)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Option Outstanding, Number Outstanding	11,094,070
Options Vested and Exercisable, Number Vested and Exercisable	6,735,086
Options Vested and Exercisable, Weighted Average Life (in Years)	5 years 7 months 17 days
$0.70 to 1.90
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Option Outstanding, Number Outstanding	998,478
Options Outstanding, Weighted Average Life (in Years)	2 years 1 month 28 days
Options Vested and Exercisable, Number Vested and Exercisable	998,478
Options Vested and Exercisable, Weighted Average Life (in Years)	2 years 1 month 28 days
Exercise Prices, Low | $ / shares	$ 0.70
Exercise Prices, High | $ / shares	$ 1.90
2.86 to 6.40
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Option Outstanding, Number Outstanding	1,173,571
Options Outstanding, Weighted Average Life (in Years)	4 years 3 months 7 days
Options Vested and Exercisable, Number Vested and Exercisable	1,173,571
Options Vested and Exercisable, Weighted Average Life (in Years)	4 years 3 months 7 days
Exercise Prices, Low | $ / shares	$ 2.86
Exercise Prices, High | $ / shares	$ 6.40
8.04 to 11.72
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Option Outstanding, Number Outstanding	1,476,371
Options Outstanding, Weighted Average Life (in Years)	5 years 2 months 23 days
Options Vested and Exercisable, Number Vested and Exercisable	1,472,047
Options Vested and Exercisable, Weighted Average Life (in Years)	5 years 2 months 23 days
Exercise Prices, Low | $ / shares	$ 8.04
Exercise Prices, High | $ / shares	$ 11.72
12.20 to 15.06
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Option Outstanding, Number Outstanding	4,696,460
Options Outstanding, Weighted Average Life (in Years)	7 years 6 months 21 days
Options Vested and Exercisable, Number Vested and Exercisable	2,926,377
Options Vested and Exercisable, Weighted Average Life (in Years)	7 years 4 months 13 days
Exercise Prices, Low | $ / shares	$ 12.20
Exercise Prices, High | $ / shares	$ 15.06
16.06 to 24.00
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Option Outstanding, Number Outstanding	2,558,590
Options Outstanding, Weighted Average Life (in Years)	9 years 1 month 13 days
Options Vested and Exercisable, Number Vested and Exercisable	163,780
Options Vested and Exercisable, Weighted Average Life (in Years)	8 years 11 months 15 days
Exercise Prices, Low | $ / shares	$ 16.06
Exercise Prices, High | $ / shares	$ 24
31.99 to 42.21
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Option Outstanding, Number Outstanding	190,600
Options Outstanding, Weighted Average Life (in Years)	9 years 7 months 17 days
Options Vested and Exercisable, Number Vested and Exercisable	833
Options Vested and Exercisable, Weighted Average Life (in Years)	9 years 11 months 1 day
Exercise Prices, Low | $ / shares	$ 31.99
Exercise Prices, High | $ / shares	$ 42.21

Equity Incentive Plans - Summ_4

Equity Incentive Plans - Summary of Fair Value Estimated Using Black-Scholes Option Pricing Model Assumptions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volatility	40.00%
Volatility, minimum		40.00%	40.00%
Volatility, maximum		43.00%	45.00%
Expected term	6 years	6 years	6 years
Risk-free interest rate, minimum	2.55%	2.02%	1.35%
Risk-free interest rate, maximum	3.10%	2.22%	2.26%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock	$ 16.86	$ 13.84	$ 12.34
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock	$ 42.21	$ 16.06	$ 13.84

Equity Incentive Plans - Summ_5

Equity Incentive Plans - Summary of RSU Activity (Details) - Restricted Stock Units	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs granted, Shares | shares	74,757
RSUs cancelled, Shares | shares	(333)
RSUs outstanding as of December 31, 2018, Shares | shares	74,424
RSUs granted, Weighted average grand date fair value per share | $ / shares	$ 32.69
RSUs cancelled, Weighted average grand date fair value per share | $ / shares	33.52
RSUs outstanding as of December 31, 2018, Weighted average grand date fair value per share | $ / shares	$ 32.69

Equity Incentive Plans - Summ_6

Equity Incentive Plans - Summary of Fair Value of ESPP Estimated Using Black-Scholes Option Pricing Model Assumptions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volatility	40.00%
Volatility, minimum		40.00%	40.00%
Volatility, maximum		43.00%	45.00%
Expected term	6 years	6 years	6 years
Risk-free interest rate, minimum	2.55%	2.02%	1.35%
Risk-free interest rate, maximum	3.10%	2.22%	2.26%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock	$ 16.86	$ 13.84	$ 12.34
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock	$ 42.21	$ 16.06	$ 13.84
2018 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volatility	40.00%
Expected term	6 months
Risk-free interest rate, minimum	2.90%
Risk-free interest rate, maximum	2.96%
2018 Employee Stock Purchase Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock	$ 24
2018 Employee Stock Purchase Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock	$ 38.18

Income Taxes - Schedule of Dome

Income Taxes - Schedule of Domestic and Foreign Components of Loss Before Income Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Domestic	$ (48,949)	$ (41,575)	$ (54,743)
Foreign	(27,577)	(23,770)	(2,505)
Loss before income taxes	$ (76,526)	$ (65,345)	$ (57,248)

Income Taxes - Schedule of Majo

Income Taxes - Schedule of Major Components of Income Tax Provision (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal	$ 0	$ 0	$ 0
State	0	0	0
Foreign	317	87	552
Total current income tax provision	317	87	552
Deferred:
Federal	(825)	(368)	435
State	64	90	38
Foreign	(532)	(1,028)	(385)
Total deferred income tax provision	(1,293)	(1,306)	88
Total	$ (976)	$ (1,219)	$ 640

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	Dec. 22, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Deferral statutory rate		21.00%	35.00%	35.00%
Amount related to re-measurement of deferred tax balance			$ 44,800,000
Amount of re-measurement that impacted deferred tax expense			700,000
Tax Cuts and Jobs Act of 2017 Incomplete accounting, provisional income tax benefit		$ 900,000
Percentage of net operating loss carryforwards		80.00%
Unrecognized tax benefits		$ 4,118,000	3,300,000	$ 2,727,000	$ 3,796,000
Unrecognized tax benefits impact effective tax rate		200,000
Income tax payments made		390,000	354,000	259,000
Foreign Subsidiaries
Income Taxes [Line Items]
Income tax payments made		400,000	400,000	$ 300,000
United States
Income Taxes [Line Items]
Research and development credit carryforwards		$ 9,100,000
Research and development credit carryforwards expiration year		2,030
GILTI
Income Taxes [Line Items]
Tax Cuts and Jobs Act of 2017, deferred amounts			0
Federal Tax
Income Taxes [Line Items]
Net operating loss		$ 342,500,000	292,200,000
Operating loss carryforwards expiration year		2,024
Additional net operating loss carryforwards		$ 49,300,000
Federal Tax | Section 382 Limitation
Income Taxes [Line Items]
Net operating loss		1,100,000
State Tax
Income Taxes [Line Items]
Net operating loss		$ 219,200,000	$ 173,900,000
Operating loss carryforwards expiration year		2,018
Maximum
Income Taxes [Line Items]
Foreign tax credit deduction percentage to offset income tax liability	50.00%

Income Taxes - Schedule of Ma_2

Income Taxes - Schedule of Major Differences Between U.S Statutory Rate and Effective Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Tax at statutory rate	$ (16,071)	$ (22,871)	$ (20,156)
State taxes	(3,375)	(2,531)	(1,863)
Research and development credits	(471)	(1,460)	(793)
Changes in tax law		(840)
Stock-based compensation	(3,246)	(3,110)	85
Goodwill impairment	3,119	2,903
Foreign rate differential	(2,488)	1,815	748
Change in valuation allowance	20,006	21,644	22,118
Intercompany intangible asset sale	1,811
Other	(261)	3,231	501
Total	$ (976)	$ (1,219)	$ 640

Income Taxes - Schedule of Sign

Income Taxes - Schedule of Significant Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Net operating loss carryforward	$ 91,529	$ 74,215
Share-based compensation	8,219	6,622
Deferred revenue	2,186	2,748
Research and development credit, net of uncertain tax position reserve	4,182	3,586
Other	7,134	2,672
Total deferred tax assets	113,250	89,843
Deferred tax liabilities:
Definite lived intangibles	(590)	(2,137)
Other	(5,368)	(1,714)
Total deferred tax liabilities	(5,958)	(3,851)
Net deferred tax assets before valuation allowance	107,292	85,992
Valuation allowance	(107,852)	(87,846)
Net deferred tax liability	$ (560)	$ (1,854)

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation of Beginning and Ending Balances for Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	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]
Balance at January 1	$ 3,300	$ 2,727	$ 3,796
Additions for tax positions related to the current year	1,446	867	242
Additions for tax positions related to prior years	0	0	0
Reductions for tax positions related to prior years	(628)	(294)	(1,311)
Reductions related to settlements	0	0	0
Reductions related to a lapse of statute	0	0	0
Balance at December 31	$ 4,118	$ 3,300	$ 2,727

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Common Shareholders - Schedule of Computation of Basic and Diluted Net Loss Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Numerator:
Net loss attributable to common shareholders	$ (75,550)	$ (64,126)	$ (57,888)
Denominator:
Weighted-average common shares outstanding-basic	38,692	5,632	5,706
Weighted-average common shares outstanding-diluted	38,692	5,632	5,706
Net loss per common share, basic and diluted	$ (1.95)	$ (11.39)	$ (10.15)

Net Loss Per Share Attributab_4

Net Loss Per Share Attributable to Common Shareholders - Schedule of Potential Shares Not Included in the Computation of Diluted Earnings 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]
Antidilutive securities excluded from computation of earnings per share amount	35,149	61,980	56,543
Options To Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	11,271	10,507	8,653
Unvested Restricted Stock Units (RSUs)
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	9
Employee Stock Purchase Plan Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	71
Preferred Stock Warrant
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount			26
Common Stock | Common Stock Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	236	580	679
Convertible Preferred Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	23,562	50,893	47,185

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) Product in Billions	Feb. 06, 2019USD ($)Product	Jan. 22, 2019USD ($)	Jan. 10, 2019USD ($)	Dec. 31, 2018USD ($)
Subsequent Event [Line Items]
Minimum lease payments due				$ 79,955,000
Subsequent Event
Subsequent Event [Line Items]
Office lease agreement date			Jan. 10, 2019
Lease incremental expiration, beginning period			2019-09
Lease incremental expiration ending period			2022-07
Minimum lease payments term			60 months
Lease term			60 months
Minimum lease payments beginning period			2019-05
Minimum lease payments due			$ 7,300,000
Security refundable deposit			$ 800,000
Subsequent Event | Compli, Inc
Subsequent Event [Line Items]
Business acquisition, date		Jan. 22, 2019
Consideration in cash		$ 13,200,000
Subsequent Event | Compli, Inc | Maximum
Subsequent Event [Line Items]
Additional consideration to be paid under earnout provision		$ 4,000,000
Subsequent Event | Indix Corporation
Subsequent Event [Line Items]
Business acquisition, date	Feb. 6, 2019
Consideration in cash	$ 7,100,000
Milestones end date	Feb. 6, 2020
Subsequent Event | Indix Corporation | Minimum
Subsequent Event [Line Items]
Products for which comprehensive product descriptions provided | Product	1
Subsequent Event | Indix Corporation | Maximum
Subsequent Event [Line Items]
Additional consideration to be paid under earnout provision	$ 3,000,000