CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenue	$ 112,282	$ 91,852	$ 322,139	$ 257,537
Cost of revenue	19,394	15,245	57,237	42,389
Gross profit	92,888	76,607	264,902	215,148
Operating expenses:
Sales and marketing	53,045	56,699	168,343	165,403
Research and development	25,128	20,763	77,269	64,396
General and administrative	18,180	17,472	54,992	48,595
Total operating expenses	96,353	94,934	300,604	278,394
Loss from operations	(3,465)	(18,327)	(35,702)	(63,246)
Interest (expense) income, net	(12)	1,527	1,177	4,677
Other expense, net	(561)	(240)	(1,819)	(576)
Loss before income taxes	(4,038)	(17,040)	(36,344)	(59,145)
Provision for income taxes	1,820	600	4,451	1,563
Net loss	$ (5,858)	$ (17,640)	$ (40,795)	$ (60,708)
Net loss per share, basic and diluted (in usd per share)	$ (0.06)	$ (0.18)	$ (0.41)	$ (0.64)
Weighted-average shares used to compute net loss per share, basic and diluted (in shares)	101,736	96,709	100,272	95,433