Annual report pursuant to Section 13 and 15(d)

Credit facilities - Additional Information (Details)

v3.20.4
Credit facilities - Additional Information (Details) - Senior Credit Facilities
 1 Months Ended 12 Months Ended
Feb. 19, 2021
USD ($)
Dec. 31, 2020
USD ($)
debt_instrument
Line of Credit Facility [Line Items]    
Number of revolving credit facilities | debt_instrument   2
Unamortized issuance costs   $ 5,000,000
Default underlying financings   50.00%
LIBOR | Default    
Line of Credit Facility [Line Items]    
Basis spread on variable rate   2.00%
Rep-Based Facility    
Line of Credit Facility [Line Items]    
Maximum outstanding amount   $ 250,000,000
Availability fee percentage   0.60%
Rep-Based Facility | U.S. Federal Government    
Line of Credit Facility [Line Items]    
Applicable valuation percentages   85.00%
Rep-Based Facility | Institutional    
Line of Credit Facility [Line Items]    
Applicable valuation percentages   80.00%
Rep-Based Facility | LIBOR    
Line of Credit Facility [Line Items]    
Basis spread on variable rate   1.40%
Fixed interest rate   1.85%
Rep-Based Facility | Federal Funds Rate    
Line of Credit Facility [Line Items]    
Basis spread on variable rate   0.40%
Fixed interest rate   0.85%
Approval-Based Facility    
Line of Credit Facility [Line Items]    
Maximum outstanding amount   $ 200,000,000
Approval-Based Facility | Certain Approved Existing Financing    
Line of Credit Facility [Line Items]    
Applicable valuation percentages   85.00%
Approval-Based Facility | Others as Prescribed by Administrative Agent    
Line of Credit Facility [Line Items]    
Applicable valuation percentages   67.00%
Approval-Based Facility | LIBOR    
Line of Credit Facility [Line Items]    
Basis spread on variable rate   1.50%
Fixed interest rate   2.00%
Approval-Based Facility | Federal Funds Rate    
Line of Credit Facility [Line Items]    
Basis spread on variable rate   0.50%
Fixed interest rate   1.00%
Unsecured Credit Facility | Subsequent Event    
Line of Credit Facility [Line Items]    
Maximum outstanding amount $ 50,000,000  
Post cash collateral (in percent) 102.00%  
Term loan fee (in percent) 2.25%  
Unsecured Credit Facility | LIBOR | Subsequent Event    
Line of Credit Facility [Line Items]    
Basis spread on variable rate 2.25%  
Variable rate, maximum downward adjustment 0.05%  
Unsecured Credit Facility | Prime Rate [Member] | Subsequent Event    
Line of Credit Facility [Line Items]    
Basis spread on variable rate 1.25%