Equity Incentive Plans - Summary of Stock-Based Compensation Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 27,896	$ 11,800	$ 50,894	$ 20,659
Cost of revenue—product
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	181	40	287	96
Cost of revenue—support
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	1,712	521	2,804	854
Research and development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	13,976	6,804	25,634	10,429
Sales and marketing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	8,732	2,536	16,251	5,980
General and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 3,295	$ 1,899	$ 5,918	$ 3,300