Employee Incentive Plans - Schedule of Stock-based Compensation Expense by Statement of Operations Location (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 14,408	$ 4,836	$ 35,292	$ 11,869
Subscription
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,421	578	3,163	1,417
Professional services and other
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	979	304	2,186	890
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	5,174	808	12,913	2,162
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3,894	1,619	9,290	4,385
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2,940	$ 1,527	$ 7,740	$ 3,015