Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss	$ (94,796)	$ (93,396)	$ (52,250)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	53,168	30,759	19,671
Amortization of deferred costs	14,373	12,609	7,982
Deferred income taxes	(12,972)	(3,478)	109
Accretion of interest on convertible senior notes	35,271	22,161	5,711
(Gain) loss on extinguishment of debt and capped call modification	(7,181)	446	1,406
Provision for credit losses and sales reserve	4,750	3,071	661
Stock-based compensation	44,095	46,755	33,489
Change in fair value of contingent consideration obligation	(7,046)	3,665	(550)
Payment of contingent consideration in excess of acquisition date fair value	(2,653)
Other non-cash adjustments	(322)	78	(241)
Change in operating assets and liabilities:
Accounts receivable	(18,187)	(22,614)	(25,558)
Prepaid expenses	(478)	(3,983)	(3,481)
Deferred costs	(16,793)	(18,902)	(15,293)
Other assets	(1,172)	146	1,758
Accounts payable	3,772	1,547	5,312
Accrued payroll and employee related liabilities	2,687	3,499	4,548
Accrued expenses	3,088	1,057	(1,308)
Deferred revenue	26,595	24,964	29,704
Other liabilities	(4,006)	7,419	(1,353)
Net cash provided by operating activities	22,193	15,803	10,317
Cash flows from investing activities:
Capital expenditures	(5,055)	(3,257)	(5,269)
Proceeds from landlord reimbursement			1,143
Payments for acquisition of business, net of acquired cash	(262,084)	(55,138)	(58,419)
Additions to capitalized software development costs	(14,697)	(9,651)	(7,819)
Purchase of short-term investments			(1,975)
Maturities of short-term investments			47,765
Purchase of intangibles		(17,139)
Net cash used in investing activities	(281,836)	(85,185)	(24,574)
Cash flows from financing activities:
Proceeds from public offering, net of costs			139,110
Proceeds from issuance of convertible notes	375,000		450,000
Payments of debt issuance costs	(10,640)	(131)	(12,686)
Purchase of convertible notes capped call hedge	(35,100)		(44,910)
Repurchase of convertible notes	(58,643)		(57,791)
Proceeds from termination of convertible notes capped call hedge	10,650		5,780
Payments of contingent consideration obligation	(2,540)
Shares withheld to settle employee tax withholding liability	(10,083)	(6,364)	(4,602)
Proceeds from employee stock purchase plan	4,587	3,389	2,337
Proceeds from option exercises	3,113	8,160	17,411
Other			(548)
Net cash provided by financing activities	276,344	5,054	494,101
Effect of exchange rates on cash, cash equivalents and restricted cash	427	296	(250)
Net increase (decrease) in cash, cash equivalents and restricted cash	17,128	(64,032)	479,594
Cash, cash equivalents and restricted cash—beginning of year	475,630	539,662	60,068
Cash, cash equivalents and restricted cash—end of year	492,758	475,630	539,662
Supplemental disclosures of cash flow information:
Interest	894	1,938	1,766
Taxes, net of refunds received	1,543	706	90
Supplemental disclosure of non-cash activities
Common stock issued in connection with acquisitions	169,541	53,193	32,798
Deferred consideration in connection with acquisition		4,044
Contingent consideration in connection with acquisitions	9,195	6,267	550
Common stock issued in connection with contingent consideration payment	7,177
Purchase accounting payable, net	1,492	(163)
Common stock issued in connection with settlement of convertible notes	17,109	11,375
Purchased intangible asset decrease	(3,027)
Capitalized assets included in accounts payable and accrued expenses	1,622	291	136
Stock-based compensation capitalized for software development	$ 589	$ 324	500
Other non-cash activities			$ 202