Share-Based Compensation - Share-Based Compensation Expense (Details) - USD ($)
$ in Thousands
3 Months Ended
Apr. 30, 2019
Apr. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Share-based compensation $ 6,296 $ 1,842
Cost of subscription revenue    
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Share-based compensation 235 34
Cost of professional services revenue    
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Share-based compensation 217 47
Research and development    
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Share-based compensation 2,272 665
Sales and marketing    
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Share-based compensation 2,108 514
General and administrative    
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Share-based compensation $ 1,464 $ 582