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, 2020	Apr. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 30,567	$ 14,009
Cost of revenue—subscription
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1,827	988
Cost of revenue—services
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1,146	593
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	10,823	4,940
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	11,759	4,520
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 5,012	$ 2,968