Equity Incentive Plans - Summary of Stock-Based Compensation Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 116,668	$ 58,225	$ 53,033
Cost of revenue—product
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	601	276	303
Cost of revenue—support
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	5,639	2,388	1,273
Research and development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	63,495	31,135	22,512
Sales and marketing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	34,317	16,966	22,466
General and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 12,616	$ 7,460	$ 6,479