Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Revenue	$ 295,066	$ 168,895	$ 803,244	$ 445,765
Cost of revenue	136,904	77,031	369,017	204,553
Gross profit	158,162	91,864	434,227	241,212
Operating expenses:
Research and development	104,481	42,340	281,119	119,727
Sales and marketing	100,657	45,949	262,685	116,520
General and administrative	47,690	28,608	166,409	76,213
Total operating expenses	252,828	116,897	710,213	312,460
Loss from operations	(94,666)	(25,033)	(275,986)	(71,248)
Other income (expense), net	4,377	(1,939)	2,861	(3,172)
Loss before provision for income taxes	(90,289)	(26,972)	(273,125)	(74,420)
Income tax benefit (provision)	2,555	(84)	56,309	(371)
Net loss attributable to common stockholders	$ (87,734)	$ (27,056)	$ (216,816)	$ (74,791)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.64)	$ (0.28)	$ (1.70)	$ (0.78)
Weighted-average shares used to compute net loss per share attributable to common stockholders, basic and diluted (in shares)	136,400,739	98,019,629	127,506,529	96,359,437