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	$ (81,787)	$ (73,293)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	32,349	36,328
Non-cash leases expense	9,824	9,958
Stock-based compensation expense, net of amounts capitalized	73,766	58,579
Deferred income taxes	293	608
Bad debt expense	898	1,156
Gain on sale of a private company investment	0	(1,001)
Other	1,048	1,834
Changes in assets and liabilities:
Accounts receivable	(2,654)	(3,929)
Prepaid expenses and other assets	(9,872)	(6,900)
Accounts payable and accrued liabilities	13,585	5,851
Accrued compensation	(7,089)	1,689
Deferred revenue	27,013	24,242
Operating lease liabilities	(11,244)	(11,135)
Net cash provided by operating activities	60,308	43,987
Cash flows from investing activities
Purchases of property and equipment	(387)	(772)
Capitalized internal-use software	(6,450)	(7,051)
Proceeds from sale of a private company investment and other	85	1,095
Net cash used in investing activities	(6,752)	(6,728)
Cash flows from financing activities
Proceeds from stock option exercises	21,334	37,301
Proceeds from employee stock purchase plan	3,873	3,082
Repayment of debt	(1,650)	(1,650)
Net cash provided by financing activities	23,557	38,733
Effect of exchange rate changes on cash	(293)	(957)
Net increase in cash, cash equivalents and restricted cash	76,820	75,035
Cash, cash equivalents and restricted cash at beginning of period	224,614	131,683
Cash, cash equivalents and restricted cash at end of period	301,434	206,718
Supplemental cash flow data:
Interest paid for term debt	6,416	7,386
Income taxes paid	732	709
Non-cash investing and financing transactions:
Stock compensation included in capitalized software costs	1,666	1,692
Lease liabilities arising from obtaining right-of-use assets, net	$ 2,676	$ 0