Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Revenue:
Product	$ 223,196	$ 160,523	$ 536,634	$ 403,181
Support	54,478	36,433	148,132	96,936
Total revenue	277,674	196,956	684,766	500,117
Cost of revenue:
Product	75,392	54,725	179,289	131,618
Support	20,467	14,597	56,569	41,531
Total cost of revenue	95,859	69,322	235,858	173,149
Gross profit	181,815	127,634	448,908	326,968
Operating expenses:
Research and development	68,927	61,612	203,716	173,185
Sales and marketing	129,299	91,392	346,896	262,073
General and administrative	25,406	22,810	67,664	64,021
Legal settlement	0	30,000	0	30,000
Total operating expenses	223,632	205,814	618,276	529,279
Loss from operations	(41,817)	(78,180)	(169,368)	(202,311)
Other income (expense), net	1,138	(192)	6,399	1,127
Loss before provision for income taxes	(40,679)	(78,372)	(162,969)	(201,184)
Provision for income taxes	970	441	2,755	967
Net loss	$ (41,649)	$ (78,813)	$ (165,724)	$ (202,151)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.20)	$ (0.40)	$ (0.79)	$ (1.05)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)	213,274	195,807	209,456	192,637