v3.26.1
Variable Interest Entities - Summary of Credit Risk Transfer Agreements (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2032
Jun. 30, 2031
Jun. 30, 2030
Jun. 30, 2029
Jun. 30, 2028
Jun. 30, 2027
Dec. 31, 2025
Credit risk transfer strips                      
Net investment income $ 72,729 $ 70,201 $ 154,863 $ 114,666              
Carrying value of credit risk transfer arrangements:                      
Interest-only security payable at fair value (34,299)   (34,299)   $ (34,299) $ 0 $ 0 $ 0 $ 0 $ 0 $ (37,650)
Variable Interest Entities [Member]                      
Carrying value of credit risk transfer arrangements:                      
Interest-only security payable at fair value (34,299)   (34,299)               (37,650)
Variable Interest Entities [Member] | Credit Risk Transfer Agreements [Member]                      
Credit risk transfer derivatives                      
Realized 2,044 2,632 4,592 5,435              
Valuation changes 215 2,743 (2,201) 1,920              
Gains recognized on gross derivative related to credit risk transactions 2,259 5,375 2,391 7,355              
Credit risk transfer strips                      
Realized 8,644 9,950 17,199 19,727              
Valuation changes (1,125) 5,524 681 (6,301)              
Credit risk transfer strips 7,519 15,474 17,880 13,426              
Interest-only security payable at fair value - valuation changes (67) (599) 3,351 (2,331)              
Gains (losses) recognized on gross derivative related to credit risk transactions 9,711 20,250 23,622 18,450              
Interest income -- Deposits securing credit risk transfer arrangements 8,481 11,401 17,373 23,076              
Net investment income 18,192 31,651 40,995 41,526              
Net payments made to settle losses on credit risk transfer arrangements 1,159 $ 1,225 2,527 $ 2,468              
Carrying value of credit risk transfer arrangements:                      
Derivative assets - credit risk transfer derivatives 30,301   30,301               32,659
Derivative and credit risk transfer liabilities - credit risk transfer strips (5,428)   (5,428)               (5,999)
Derivative and credit risk transfer strip assets 938,474   938,474               998,344
Deposits securing credit risk transfer arrangements 947,900   947,900               1,009,334
Interest-only security payable at fair value (34,299)   (34,299)               (37,650)
Derivative assets 30,301   30,301               32,659
Derivative and credit risk transfer strip assets pledged to secure [1] 947,900   947,900               1,009,334
Unpaid principal balance of loans underlying credit risk transfer arrangements 18,089,855   18,089,855               19,517,530
Variable Interest Entities [Member] | Credit Risk Transfer Agreements [Member] | Purchase Commitment [Member]                      
Collection status (unpaid principal balance):                      
Current 17,597,227   17,597,227               18,908,261
30-89 days delinquent 340,562   340,562               413,295
90-179 days delinquent 79,095   79,095               110,486
180 or more days delinquent 51,370   51,370               57,798
Foreclosure 21,601   21,601               27,690
Bankruptcy $ 56,129   $ 56,129               $ 68,426
[1] Deposits securing credit risk transfer arrangements also secure $5.4 million and $6.0 million in CRT strip liabilities at June 30, 2026 and December 31, 2025, respectively.