Equity Incentive Plans and Employee Stock Purchase Plan - Stock-based Compensation Expense Recognized in Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2018	Apr. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 7,577	$ 4,454
Cost of revenue—subscription
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	359	151
Cost of revenue—services
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	184	72
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	2,218	1,215
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	2,206	1,245
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 2,610	$ 1,771