Equity Incentive Plans - Summary of Stock-Based Compensation Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2016	Oct. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 28,235	$ 15,539	$ 79,129	$ 36,198
Cost of revenue—product
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	138	43	425	139
Cost of revenue—support
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	1,178	657	3,982	1,511
Research and development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	15,241	8,195	40,875	18,624
Sales and marketing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	8,468	4,559	24,719	10,539
General and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 3,210	$ 2,085	$ 9,128	$ 5,385