Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net loss	$ (84,288)	$ (68,810)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	38,080	22,116
Amortization of deferred costs	10,398	9,152
Deferred income taxes	(11,232)	(2,310)
Accretion of interest on convertible senior notes	25,470	16,527
Loss on extinguishment of convertible notes and capped call modification	2,925	44
Provision for credit losses and sales reserve	2,679	1,442
Stock-based compensation	45,631	34,939
Change in fair value of contingent consideration obligation	(7,046)	1,500
Payment of contingent consideration in excess of acquisition date fair value	(2,653)
Other non-cash adjustments	13	(81)
Changes in operating assets and liabilities:
Accounts receivable	16,020	(7,929)
Prepaid expenses	93	(4,752)
Deferred costs	(11,387)	(12,000)
Other assets	(6,525)	(3,248)
Accounts payable	(3,535)	2,286
Accrued payroll and employee related liabilities	(3,812)	3,965
Accrued expenses	2,836	(1)
Deferred revenue	3,744	1,107
Other liabilities	(5,430)	2,457
Net cash provided by (used in) operating activities	11,981	(3,596)
Cash flows from investing activities:
Capital expenditures	(4,170)	(2,122)
Payments for acquisition of business, net of acquired cash	(199,679)	(54,757)
Additions to capitalized software development costs	(8,879)	(7,296)
Net cash used in investing activities	(212,728)	(64,175)
Cash flows from financing activities:
Proceeds from issuance of convertible notes	375,000
Payments of debt issuance costs	(10,640)	(131)
Purchase of convertible notes capped call hedge	(35,100)
Repurchase of convertible notes	(58,641)
Proceeds from termination of convertible notes capped call hedge	10,650
Payment of contingent consideration	(2,540)
Restricted stock units withheld to settle employee tax withholding liability	(6,399)	(4,269)
Proceeds from employee stock purchase plan	4,587	3,389
Proceeds from stock option exercises	2,947	6,764
Net cash provided by financing activities	279,864	5,753
Effect of exchange rates on cash, cash equivalents and restricted cash	219	(411)
Net increase (decrease) in cash, cash equivalents and restricted cash	79,336	(62,429)
Cash, cash equivalents and restricted cash—beginning of period	475,630	539,662
Cash, cash equivalents and restricted cash—end of period	554,966	477,233
Supplemental disclosures of cash flow information:
Interest	610	974
Taxes, net of refunds received	1,564	577
Supplemental disclosure of non-cash activities:
Common stock issued in connection with acquisitions	89,287	53,193
Deferred consideration in connection with acquisition		4,044
Contingent consideration in connection with acquisitions	9,135	6,267
Common stock issued in connection with contingent consideration payment	7,177
Common stock issued in connection with settlement of convertible notes	16,826	938
Stock-based compensation capitalized for software development costs	406	243
Other non-cash activities	$ 365	$ 71