v3.20.1
Commitment and Contingencies (Details) - USD ($)
12 Months Ended
Jan. 31, 2020
Jan. 31, 2019
Jan. 31, 2018
Line of Credit Facility [Line Items]      
Rent expense $ 10,300,000 $ 6,900,000 $ 4,600,000
Commitment to spend 166,000,000.0    
Loss contingency recorded 0 0  
Indemnification Agreement      
Line of Credit Facility [Line Items]      
Loss contingency recorded 0 0  
CALIFORNIA | Standby Letters of Credit      
Line of Credit Facility [Line Items]      
Unused standby letter of credit 600,000 500,000  
TEXAS | Standby Letters of Credit      
Line of Credit Facility [Line Items]      
Unused standby letter of credit $ 1,000,000.0 $ 800,000