v3.20.1
Secured Revolving Credit Facility (Details)
1 Months Ended
Apr. 30, 2019
USD ($)
unit_Standard_item
Jan. 31, 2020
USD ($)
Minimum    
Line of Credit Facility [Line Items]    
Commitment fee percentage 0.20%  
Maximum    
Line of Credit Facility [Line Items]    
Commitment fee percentage 0.30%  
Revolving Credit Facility    
Line of Credit Facility [Line Items]    
Revolving line of credit $ 150,000,000.0  
Incremental borrowing capacity $ 75,000,000.0  
Borrowing facility multiple factor - first year | unit_Standard_item 6  
Borrowing facility multiple factor - second year | unit_Standard_item 5  
Borrowing facility multiple factor - third year | unit_Standard_item 4  
Line of credit amount outstanding   $ 0
Letter of Credit    
Line of Credit Facility [Line Items]    
Revolving line of credit $ 10,000,000.0  
Swingline Facility    
Line of Credit Facility [Line Items]    
Revolving line of credit $ 10,000,000.0  
Alternate Base Rate Loans | Fed Funds Effective Rate Overnight Index Swap Rate    
Line of Credit Facility [Line Items]    
Interest rate 0.50%  
Alternate Base Rate Loans | Eurodollar    
Line of Credit Facility [Line Items]    
Interest rate 1.00%  
Alternate Base Rate Loans | Eurodollar | Minimum    
Line of Credit Facility [Line Items]    
Interest rate 1.50%  
Alternate Base Rate Loans | Eurodollar | Maximum    
Line of Credit Facility [Line Items]    
Interest rate 2.00%  
Eurodollar Loans | London Interbank Offered Rate (LIBOR) | Minimum    
Line of Credit Facility [Line Items]    
Interest rate 2.50%  
Eurodollar Loans | London Interbank Offered Rate (LIBOR) | Maximum    
Line of Credit Facility [Line Items]    
Interest rate 3.00%