Employee Incentive Plans - Schedule of Stock-based Compensation Expense by Statement of Operations Location (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 11,978	$ 3,664	$ 20,884	$ 7,033
Subscription
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,056	446	1,742	839
Professional services and other
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	738	313	1,207	586
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	4,438	736	7,739	1,354
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3,021	1,412	5,396	2,766
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2,725	$ 757	$ 4,800	$ 1,488