Quarterly report pursuant to Section 13 or 15(d)

Fair Value - Summary of Commercial Mortgage Single Rental Loans (Detail)

v3.21.2
Fair Value - Summary of Commercial Mortgage Single Rental Loans (Detail) - Commercial Mortgage Single Rental Loans [Member]
6 Months Ended 12 Months Ended
Jun. 30, 2021
Dec. 31, 2020
Minimum [Member] | Prepayment Rate [Member]    
Fair Value Single Rental Loan SRL Classified Under Mortgage Loans Held For Sale Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Prepayment rate (CPR) 1.00% 1.00%
Minimum [Member] | Default Rate [Member]    
Fair Value Single Rental Loan SRL Classified Under Mortgage Loans Held For Sale Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Default rate (CDR) 1.00% 1.00%
Maximum [Member] | Prepayment Rate [Member]    
Fair Value Single Rental Loan SRL Classified Under Mortgage Loans Held For Sale Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Prepayment rate (CPR) 17.00% 17.10%
Maximum [Member] | Default Rate [Member]    
Fair Value Single Rental Loan SRL Classified Under Mortgage Loans Held For Sale Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Default rate (CDR) 54.00% 64.90%
Weighted Average [Member] | Prepayment Rate [Member]    
Fair Value Single Rental Loan SRL Classified Under Mortgage Loans Held For Sale Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Prepayment rate (CPR) 14.00% 15.40%
Weighted Average [Member] | Discount rate [Member]    
Fair Value Single Rental Loan SRL Classified Under Mortgage Loans Held For Sale Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Discount rate 3.30% 5.00%
Weighted Average [Member] | Default Rate [Member]    
Fair Value Single Rental Loan SRL Classified Under Mortgage Loans Held For Sale Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Default rate (CDR) 2.40% 3.60%