Common Stock - Schedule of Total Stock-Based Compensation Expense Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Stock-based compensation:
Total stock-based compensation expense	$ 11,852	$ 3,301	$ 37,770	$ 10,742
Cost of Product Revenue
Stock-based compensation:
Total stock-based compensation expense	334	68	1,095	197
Cost of Support and Maintenance Revenue
Stock-based compensation:
Total stock-based compensation expense	358	71	1,011	243
Research and development
Stock-based compensation:
Total stock-based compensation expense	5,116	1,230	14,772	4,090
Sales and marketing
Stock-based compensation:
Total stock-based compensation expense	2,468	959	8,150	3,209
General and administrative
Stock-based compensation:
Total stock-based compensation expense	$ 3,576	$ 973	$ 12,742	$ 3,003