Quarterly report pursuant to Section 13 or 15(d)

Fair Value - Summary of HECM Buyouts (Detail)

v3.21.2
Fair Value - Summary of HECM Buyouts (Detail) - HECM Buyouts [Member]
 6 Months Ended 12 Months Ended
Jun. 30, 2021
Dec. 31, 2020
Minimum [Member] | Loss frequency [Member]    
Fair Value HECM Buyouts Securitized Nonperforming Mortgage Loans Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Loss frequency 25.00% 25.00%
Minimum [Member] | Loss severity [Member]    
Fair Value HECM Buyouts Securitized Nonperforming Mortgage Loans Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Loss severity 4.90% 5.10%
Maximum [Member] | Loss frequency [Member]    
Fair Value HECM Buyouts Securitized Nonperforming Mortgage Loans Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Loss frequency 100.00% 100.00%
Maximum [Member] | Loss severity [Member]    
Fair Value HECM Buyouts Securitized Nonperforming Mortgage Loans Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Loss severity 11.70% 13.30%
Weighted Average [Member] | Conditional repayment rate [Member]    
Fair Value HECM Buyouts Securitized Nonperforming Mortgage Loans Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Conditional repayment rate 40.60% 42.90%
Weighted Average [Member] | Loss frequency [Member]    
Fair Value HECM Buyouts Securitized Nonperforming Mortgage Loans Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Loss frequency 52.50% 54.80%
Weighted Average [Member] | Loss severity [Member]    
Fair Value HECM Buyouts Securitized Nonperforming Mortgage Loans Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Loss severity 7.00% 7.50%
Discount rate 3.60% 4.10%