Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Revenue:
Product	$ 813,985	$ 590,001	$ 375,733
Support	209,034	137,976	64,600
Total revenue	1,023,019	727,977	440,333
Cost of revenue:
Product	275,242	194,150	132,870
Support	78,539	58,129	35,023
Total cost of revenue	353,781	252,279	167,893
Gross profit	669,238	475,698	272,440
Operating expenses:
Research and development	279,196	245,817	166,645
Sales and marketing	480,030	360,035	240,574
General and administrative	95,170	84,652	75,402
Legal settlement	0	30,000	0
Total operating expenses	854,396	720,504	482,621
Loss from operations	(185,158)	(244,806)	(210,181)
Other income (expense), net	11,445	1,627	(2,002)
Loss before provision for income taxes	(173,713)	(243,179)	(212,183)
Provision for income taxes	3,889	1,887	1,569
Net loss	$ (177,602)	$ (245,066)	$ (213,752)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.84)	$ (1.26)	$ (2.59)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)	211,609	194,714	82,460