Quarterly report pursuant to Section 13 or 15(d)

Fair Value - Summary of Non-Agency Reverse Mortgage Securitized (Detail)

v3.22.2
Fair Value - Summary of Non-Agency Reverse Mortgage Securitized (Detail) - Non Agency Reverse Mortgage Securitized [Member]
6 Months Ended 12 Months Ended
Jun. 30, 2022
Dec. 31, 2021
Minimum [Member] | Loan to value [Member]    
Fair Value Non Agency Reverse Mortgage Loan Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Loan to value 0.10% 0.10%
Minimum [Member] | Home price appreciation [Member]    
Fair Value Non Agency Reverse Mortgage Loan Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Home price appreciation 10.10% 4.60%
Maximum [Member] | Loan to value [Member]    
Fair Value Non Agency Reverse Mortgage Loan Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Loan to value 73.00% 64.70%
Maximum [Member] | Home price appreciation [Member]    
Fair Value Non Agency Reverse Mortgage Loan Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Home price appreciation 11.00% 14.00%
Weighted Average [Member] | Weighted average remaining life in years [Member]    
Fair Value Non Agency Reverse Mortgage Loan Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Weighted-average remaining life in years 9 years 3 months 18 days 7 years 6 months
Weighted Average [Member] | Loan to value [Member]    
Fair Value Non Agency Reverse Mortgage Loan Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Loan to value 42.90% 43.40%
Weighted Average [Member] | Conditional repayment rate [Member]    
Fair Value Non Agency Reverse Mortgage Loan Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Conditional repayment rate 14.70% 18.60%
Weighted Average [Member] | Loss severity [Member]    
Fair Value Non Agency Reverse Mortgage Loan Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Loss severity 10.00% 10.00%
Weighted Average [Member] | Home price appreciation [Member]    
Fair Value Non Agency Reverse Mortgage Loan Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Home price appreciation 4.90% 4.70%
Weighted Average [Member] | Discount rate [Member]    
Fair Value Non Agency Reverse Mortgage Loan Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]    
Discount rate 6.20% 3.60%