Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net loss	$ (55,610)	$ (44,605)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	23,854	13,976
Amortization of deferred costs	7,184	5,735
Deferred income taxes	(9,778)	(3,014)
Accretion of interest on debt	15,821	10,949
Loss on extinguishment of convertible notes and capped call modification	2,925
Provision for credit losses and sales reserve	1,905	1,387
Stock-based compensation	28,190	21,588
Other non-cash adjustments	(32)
Changes in operating assets and liabilities:
Accounts receivable	19,312	3,341
Prepaid expenses	(922)	(3,265)
Deferred costs	(8,107)	(6,943)
Other assets	(850)	(3,429)
Accounts payable	(60)	2,164
Accrued payroll and employee related liabilities	(5,320)	(334)
Accrued expenses	971	(593)
Deferred revenue	(180)	(2,722)
Other liabilities	(4,632)	2,696
Net cash provided by (used in) operating activities	14,671	(3,069)
Cash flows from investing activities:
Capital expenditures	(2,128)	(1,175)
Payments for acquisition of business, net of acquired cash	(197,666)	(44,265)
Additions to capitalized software development costs	(6,082)	(4,673)
Net cash used in investing activities	(205,876)	(50,113)
Cash flows from financing activities:
Proceeds from issuance of convertible notes	375,000
Payments of debt issuance costs	(10,391)	(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
Restricted stock units withheld to settle employee tax withholding liability	(2,843)	(927)
Proceeds from employee stock purchase plan	2,451	1,710
Proceeds from stock option exercises	2,163	4,585
Net cash provided by financing activities	283,289	5,237
Effect of exchange rates on cash, cash equivalents and restricted cash	588	(419)
Net increase (decrease) in cash, cash equivalents and restricted cash	92,672	(48,364)
Cash, cash equivalents and restricted cash—beginning of period	475,630	539,662
Cash, cash equivalents and restricted cash—end of period	568,302	491,298
Supplemental disclosures of cash flow information:
Interest	610	974
Taxes, net of refunds received	935	476
Supplemental disclosure of non-cash activities:
Common stock issued in connection with acquisitions	87,514	35,508
Deferred consideration in connection with acquisition		895
Purchase accounting payable, net		619
Contingent consideration in connection with acquisitions	9,135	4,220
Common stock issued in connection with contingent consideration	720
Common stock issued in connection with settlement of convertible notes	16,826
Debt issuance costs included in accrued expenses	250
Stock-based compensation capitalized for software development costs	215	152
Other non-cash activities	$ 220	$ 376