Quarterly report pursuant to Section 13 or 15(d)

Fair Value - Additional Information (Detail)

v3.21.2
Fair Value - Additional Information (Detail)
9 Months Ended
Sep. 30, 2021
Dec. 31, 2020
Single Rental Loan Classified Under Mortgage Loans Held For Sale [Member]    
Additional Information [Line Items]    
Debt instrument term 30 years  
Portfolio Lending Classified Under Mortgage Loans Held For Sale [Member] | Five Years [Member]    
Additional Information [Line Items]    
Debt instrument, Balloon structure period 5.00%  
Portfolio Lending Classified Under Mortgage Loans Held For Sale [Member] | Ten Years [Member]    
Additional Information [Line Items]    
Debt instrument, Balloon structure period 10.00%  
Portfolio Lending Classified Under Mortgage Loans Held For Sale [Member] | Thirty Years [Member]    
Additional Information [Line Items]    
Debt instrument, Balloon structure period 30.00%  
Maximum [Member]    
Additional Information [Line Items]    
Discount rates utilized to value deferred purchase price liability   30.00%
Maximum [Member] | Fix And Flip Loans Classified Under Mortgage Loans Held For Investment Subject To Nonrecourse Debt [Member]    
Additional Information [Line Items]    
Debt instrument term 24 months  
Maximum [Member] | Agricultural Loans [Member]    
Additional Information [Line Items]    
Debt instrument term 17 months  
Maximum [Member] | Fix And Flip Loans Classified Under Mortgage Loans Held For Investment [Member]    
Additional Information [Line Items]    
Debt instrument term 24 months  
Maximum [Member] | Single Rental Loan Classified Under Mortgage Loans Held For Sale [Member]    
Additional Information [Line Items]    
Debt instrument, Stated interest rate 8.00%  
Maximum [Member] | Portfolio Lending Classified Under Mortgage Loans Held For Sale [Member]    
Additional Information [Line Items]    
Debt instrument, Fixed coupon rate 6.20%  
Minimum [Member]    
Additional Information [Line Items]    
Discount rates utilized to value deferred purchase price liability   12.00%
Minimum [Member] | Fix And Flip Loans Classified Under Mortgage Loans Held For Investment Subject To Nonrecourse Debt [Member]    
Additional Information [Line Items]    
Debt instrument term 9 months  
Minimum [Member] | Agricultural Loans [Member]    
Additional Information [Line Items]    
Debt instrument term 7 months  
Minimum [Member] | Fix And Flip Loans Classified Under Mortgage Loans Held For Investment [Member]    
Additional Information [Line Items]    
Debt instrument term 9 months  
Minimum [Member] | Single Rental Loan Classified Under Mortgage Loans Held For Sale [Member]    
Additional Information [Line Items]    
Debt instrument, Stated interest rate 5.00%  
Minimum [Member] | Portfolio Lending Classified Under Mortgage Loans Held For Sale [Member]    
Additional Information [Line Items]    
Debt instrument, Fixed coupon rate 5.00%  
Minimum [Member] | Fix And Flip Loans Classified Under Mortgage Loans Held For Sale [Member]    
Additional Information [Line Items]    
Debt instrument term 9 months  
Mortgage Servicing Rights Financing Liability [Member]    
Additional Information [Line Items]    
Cumulative Percentage Change In Fair Value Of Servicing Rights Liabilities 10.00%  
TRA Obligation [Member] | Measurement Input, Discount Rate [Member]    
Additional Information [Line Items]    
TRA obligation measurement input 12