CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Revenue	$ 541,130	$ 440,221	$ 354,586
Cost of revenue	106,396	77,554	60,818
Gross profit	434,734	362,667	293,768
Operating expenses:
Sales and marketing	270,158	224,277	228,035
Research and development	116,432	101,687	87,064
General and administrative	89,912	73,136	69,468
Total operating expenses	476,502	399,100	384,567
Loss from operations	(41,768)	(36,433)	(90,799)
Interest (expense) income, net	(6,896)	1,244	5,830
Other expense, net	(1,965)	(1,885)	(680)
Loss before income taxes	(50,629)	(37,074)	(85,649)
(Benefit) provision for income taxes	(3,952)	5,657	13,364
Net loss	$ (46,677)	$ (42,731)	$ (99,013)
Net loss per share, basic (in usd per share)	$ (0.44)	$ (0.42)	$ (1.03)
Net loss per share, diluted (in usd per share)	$ (0.44)	$ (0.42)	$ (1.03)
Weighted-average shares used to compute net loss per share, basic (in shares)	106,387	101,009	96,014
Weighted-average shares used to compute net loss per share, diluted (in shares)	106,387	101,009	96,014