CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Revenue	$ 107,209	$ 85,384	$ 209,857	$ 165,685
Cost of revenue	19,142	13,918	37,843	27,144
Gross profit	88,067	71,466	172,014	138,541
Operating expenses:
Sales and marketing	55,443	56,015	115,298	108,704
Research and development	25,310	21,698	52,141	43,633
General and administrative	17,879	15,987	36,812	31,123
Total operating expenses	98,632	93,700	204,251	183,460
Loss from operations	(10,565)	(22,234)	(32,237)	(44,919)
Interest income, net	455	1,594	1,189	3,150
Other expense, net	(298)	(122)	(1,258)	(336)
Loss before income taxes	(10,408)	(20,762)	(32,306)	(42,105)
Provision for income taxes	1,552	866	2,631	963
Net loss	$ (11,960)	$ (21,628)	$ (34,937)	$ (43,068)
Net loss per share, basic and diluted (in usd per share)	$ (0.12)	$ (0.23)	$ (0.35)	$ (0.45)
Weighted-average shares used to compute net loss per share, basic and diluted (in shares)	100,209	95,820	99,532	94,785