v3.26.1
Variable Interest Entities - Summary of Credit Risk Transfer Agreements (Detail) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2032
Mar. 31, 2031
Mar. 31, 2030
Mar. 31, 2029
Mar. 31, 2028
Mar. 31, 2027
Dec. 31, 2025
Credit risk transfer strips                  
Net investment income $ 82,134 $ 44,465              
Carrying value of credit risk transfer arrangements:                  
Interest-only security payable at fair value (34,232)   $ (34,232) $ 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 (34,232)               (37,650)
Variable Interest Entities [Member] | Credit Risk Transfer Agreements [Member]                  
Credit risk transfer derivatives                  
Realized 2,548 2,803              
Valuation changes (2,416) (823)              
Gains recognized on gross derivative related to credit risk transactions 132 1,980              
Credit risk transfer strips                  
Realized 8,555 9,777              
Valuation changes 1,806 (11,825)              
Credit risk transfer strips 10,361 (2,048)              
Interest-only security payable at fair value - valuation changes 3,418 (1,732)              
Gains (losses) recognized on gross derivative related to credit risk transactions 13,911 (1,800)              
Interest income -- Deposits securing credit risk transfer arrangements 8,892 11,675              
Net investment income 22,803 9,875              
Net payments made to settle losses on credit risk transfer arrangements 1,368 $ 1,243              
Carrying value of credit risk transfer arrangements:                  
Derivative assets - credit risk transfer derivatives 30,174               32,659
Derivative and credit risk transfer liabilities - credit risk transfer strips (4,062)               (5,999)
Derivative and credit risk transfer strip assets 961,605               998,344
Deposits securing credit risk transfer arrangements 969,725               1,009,334
Interest-only security payable at fair value (34,232)               (37,650)
Derivative assets 30,174               32,659
Derivative and credit risk transfer strip assets pledged to secure [1] 969,725               1,009,334
Unpaid principal balance of loans underlying credit risk transfer arrangements 18,715,937               19,517,530
Variable Interest Entities [Member] | Credit Risk Transfer Agreements [Member] | Purchase Commitment [Member]                  
Collection status (unpaid principal balance):                  
Current 18,166,705               18,908,261
30-89 days delinquent 363,958               413,295
90-179 days delinquent 96,209               110,486
180 or more days delinquent 62,748               57,798
Foreclosure 26,317               27,690
Bankruptcy $ 60,687               $ 68,426
[1] Deposits securing credit risk transfer arrangements also secure $4.1 million and $6.0 million in CRT strip liabilities at March 31, 2026 and December 31, 2025, respectively.