Annual report pursuant to Section 13 and 15(d)

Borrowings - Terms of MetLife Facility (Detail)

v3.22.0.1
Borrowings - Terms of MetLife Facility (Detail) - USD ($)
12 Months Ended
Dec. 31, 2021
Dec. 31, 2019
Debt Instrument [Line Items]    
Principal Outstanding $ 671,573,000  
MetLife Credit Facility    
Debt Instrument [Line Items]    
Aggregate Commitment   $ 200,000,000
Principal Outstanding 37,000,000  
MetLife Credit Facility | Notes payable to bank    
Debt Instrument [Line Items]    
Aggregate Commitment 75,000,000  
Principal Outstanding $ 36,900,000  
Interest Rate Terms 2.75%  
Undrawn Commitment $ 38,100,000 $ 21,500,000
MetLife Credit Facility | Notes payable to bank | Minimum    
Debt Instrument [Line Items]    
Unused fee 0.10%  
MetLife Credit Facility | Notes payable to bank | Maximum    
Debt Instrument [Line Items]    
Unused fee 0.20%  
MetLife Credit Facility | Line of credit    
Debt Instrument [Line Items]    
Aggregate Commitment $ 75,000,000  
Principal Outstanding 100,000  
Undrawn Commitment 74,900,000  
Long-term debt, additional amount available $ 58,400,000  
Minimum annualized rate 2.50%  
MetLife Credit Facility | Line of credit | Minimum    
Debt Instrument [Line Items]    
Unused fee 0.10%  
MetLife Credit Facility | Line of credit | Maximum    
Debt Instrument [Line Items]    
Unused fee 0.20%  
MetLife Credit Facility | Line of credit | LIBOR    
Debt Instrument [Line Items]    
Interest Rate Terms 2.00%