XML 67 R84.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Net Loss Per Share Narrative (Details) - $ / shares
Jan. 31, 2020
Feb. 28, 2018
Convertible Senior Notes Due 2023    
Debt Instrument [Line Items]    
Class of warrant or right, exercise price of warrants or rights   $ 68.06
Convertible Senior Notes Due 2023 | Senior Notes    
Debt Instrument [Line Items]    
Conversion price (in dollars per share)   $ 48.36
Convertible Senior Notes Due 2025 | Senior Notes    
Debt Instrument [Line Items]    
Conversion price (in dollars per share) $ 188.71