XML 56 R51.htm IDEA: XBRL DOCUMENT v3.19.3
Net Loss per Share - Additional Information (Details) - shares
 9 Months Ended
Jun. 15, 2018
Oct. 31, 2019
Jan. 31, 2019
Jun. 14, 2018
Class Of Stock [Line Items]        
Common Stock, conversion features   On June 14, 2018, all of our outstanding shares of Class B common stock automatically converted into the same number of shares of Class A common stock pursuant to the terms of our Amended and Restated Certificate of Incorporation. No additional shares of Class B common stock will be issued following such conversion. The conversion occurred pursuant to Article IV of the Amended and Restated Certificate of Incorporation, which provided that each one share of Class B common stock would convert automatically, without any further action, into one share of Class A common stock on the first trading day falling on or after the date on which the outstanding shares of Class B common stock represent less than 5% of the aggregate number of shares of the then outstanding Class A common stock and Class B common stock.    
Additional common shares issued   149,478,000 144,311,000  
Class B Common Stock        
Class Of Stock [Line Items]        
Maximum percentage of outstanding shares of Class A and Class B common stock, for automatic conversion of shares of Class B common stock       5.00%
Additional common shares issued       0
Reduction in number of authorized shares of common stock 200,000,000