v3.25.2
Variable Interest Entities - Summary of Credit Risk Transfer Agreements (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2031
Jun. 30, 2030
Jun. 30, 2029
Jun. 30, 2028
Jun. 30, 2027
Jun. 30, 2026
Dec. 31, 2024
Credit risk transfer strips                      
Net investment income $ 70,201 $ 71,198 $ 114,666 $ 145,403              
Carrying value of credit risk transfer arrangements:                      
Interest-only security payable at fair value (36,553)   (36,553)   $ (36,553) $ 0 $ 0 $ 0 $ 0 $ 0 $ (34,222)
Variable Interest Entities [Member]                      
Carrying value of credit risk transfer arrangements:                      
Interest-only security payable at fair value (36,553)   (36,553)               (34,222)
Variable Interest Entities [Member] | Credit Risk Transfer Agreements [Member]                      
Credit risk transfer derivatives                      
Realized 2,632 3,564 5,435 6,973              
Valuation changes 2,743 1,475 1,920 8,256              
Gains recognized on gross derivative related to credit risk transactions 5,375 5,039 7,355 15,229              
Credit risk transfer strips                      
Realized 9,950 11,693 19,727 23,378              
Valuation changes 5,524 378 (6,301) 29,718              
Credit risk transfer strips 15,474 12,071 13,426 53,096              
Interest-only security payable at fair value - valuation changes (599) (481) (2,331) (41)              
Gains (losses) recognized on gross derivative related to credit risk transactions 20,250 16,629 18,450 68,284              
Interest income -- Deposits securing credit risk transfer arrangements 11,401 15,383 23,076 31,079              
Net investment income 31,651 32,012 41,526 99,363              
Net payments made to settle losses on credit risk transfer arrangements 1,225 $ 128 2,468 $ 313              
Carrying value of credit risk transfer arrangements:                      
Derivative assets - credit risk transfer derivatives 31,147   31,147               29,377
Derivative and credit risk transfer liabilities - credit risk transfer strip liabilities (10,479)   (10,479)               (4,060)
Derivative and credit risk transfer strip assets 1,048,834   1,048,834               1,101,803
Deposits securing credit risk transfer arrangements 1,064,719   1,064,719               1,110,708
Interest-only security payable at fair value (36,553)   (36,553)               (34,222)
Derivative assets 31,147   31,147               29,377
Derivative and credit risk transfer strip assets pledged to secure [1] 1,064,719   1,064,719               1,110,708
Unpaid principal balance of loans underlying credit risk transfer arrangements 20,356,165   20,356,165               21,249,304
Variable Interest Entities [Member] | Credit Risk Transfer Agreements [Member] | Purchase Commitment [Member]                      
Collection status (unpaid principal balance):                      
Current 19,791,362   19,791,362               20,628,148
30-89 days delinquent 386,978   386,978               414,605
90-179 days delinquent 106,898   106,898               131,191
180 or more days delinquent 46,254   46,254               51,343
Foreclosure 24,673   24,673               24,017
Bankruptcy $ 65,532   $ 65,532               $ 63,697
[1] Deposits securing credit risk transfer arrangements also secure $10.5 million and $4.1 million in CRT strip liabilities at June 30, 2025 and December 31, 2024, respectively.