CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Revenue	$ 91,250	$ 61,727
Cost of revenue	20,821	14,360
Gross profit	70,429	47,367
Operating expenses:
Sales and marketing	46,965	30,817
Research and development	33,354	17,649
General and administrative	26,181	16,048
Total operating expenses	106,500	64,514
Loss from operations	(36,071)	(17,147)
Non-operating income:
Interest income	2,569	913
Interest expense	(67)	(273)
Other income (expense), net	485	(293)
Total non-operating income, net	2,987	347
Loss before income taxes	(33,084)	(16,800)
Provision for (benefit from) income taxes	(338)	314
Net loss	$ (32,746)	$ (17,114)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.11)	$ (0.20)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)	296,077	85,078