Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016
Revenue:
Product	$ 175,013	$ 130,920	$ 313,438	$ 242,658
Support	49,448	32,294	93,654	60,503
Total revenue	224,461	163,214	407,092	303,161
Cost of revenue:
Product	57,252	42,847	103,897	76,893
Support	19,199	14,000	36,102	26,934
Total cost of revenue	76,451	56,847	139,999	103,827
Gross profit	148,010	106,367	267,093	199,334
Operating expenses:
Research and development	69,361	58,635	134,789	111,573
Sales and marketing	120,633	87,583	217,597	170,681
General and administrative	22,162	19,630	42,258	41,211
Total operating expenses	212,156	165,848	394,644	323,465
Loss from operations	(64,146)	(59,481)	(127,551)	(124,131)
Other income, net	3,266	37	5,261	1,319
Loss before provision for income taxes	(60,880)	(59,444)	(122,290)	(122,812)
Provision for income taxes	821	106	1,785	526
Net loss	$ (61,701)	$ (59,550)	$ (124,075)	$ (123,338)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.29)	$ (0.31)	$ (0.60)	$ (0.65)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)	209,193	192,730	207,515	191,026