v3.25.2
Fair Value - Fair Values and Related Principal Amounts Due upon Maturity of Loans Accounted for Under Fair Value Option (Detail) - USD ($)
$ in Thousands
Jun. 30, 2025
Dec. 31, 2024
Loans, fair value [Abstract]    
Fair value $ 4,566,532 $ 2,193,575
Fair value, Total 4,566,532 2,193,575
Loans, principal amount due upon maturity [Abstract]    
Principal amount due upon maturity 4,652,259 2,419,263
Loans, difference, [Abstract]    
Difference (85,727) (225,688)
Loans acquired for sale [Member]    
Loans, fair value [Abstract]    
Current through 89 days delinquent 2,614,499 2,114,556
90 or more days delinquent, not in foreclosure 910 1,687
90 or more days delinquent, in foreclosure 842 75
Fair value, Total 2,616,251 2,116,318
Loans, principal amount due upon maturity [Abstract]    
Current through 89 days delinquent 2,550,108 2,092,030
90 or more days delinquent, not in foreclosure 941 2,114
90 or more days delinquent, in foreclosure 1,002 96
Principal amount due upon maturity 2,552,051 2,094,240
Loans, difference, [Abstract]    
Current through 89 days delinquent 64,391 22,526
90 or more days delinquent, not in foreclosure (31) (427)
90 or more days delinquent, in foreclosure (160) (21)
Difference 64,200 22,078
Loans acquired for sale [Member] | Nonperforming mortgage loans [Member]    
Loans, fair value [Abstract]    
Fair value 1,752 1,762
Loans, principal amount due upon maturity [Abstract]    
Principal amount due upon maturity 1,943 2,210
Loans, difference, [Abstract]    
Difference (191) (448)
Loans Held for Investment Held in Consolidated VIE [Member]    
Loans, fair value [Abstract]    
Current through 89 days delinquent 4,563,339 2,190,432
90 or more days delinquent, not in foreclosure 1,339 1,277
90 or more days delinquent, in foreclosure 0 0
Fair value, Total 4,564,678 2,191,709
Loans, principal amount due upon maturity [Abstract]    
Current through 89 days delinquent 4,646,273 2,413,214
90 or more days delinquent, not in foreclosure 1,635 1,658
90 or more days delinquent, in foreclosure 0 0
Principal amount due upon maturity 4,647,908 2,414,872
Loans, difference, [Abstract]    
Current through 89 days delinquent (82,934) (222,782)
90 or more days delinquent, not in foreclosure (296) (381)
90 or more days delinquent, in foreclosure 0 0
Difference (83,230) (223,163)
Loans Held for Investment Held in Consolidated VIE [Member] | Nonperforming mortgage loans [Member]    
Loans, fair value [Abstract]    
Fair value 1,339 1,277
Loans, principal amount due upon maturity [Abstract]    
Principal amount due upon maturity 1,635 1,658
Loans, difference, [Abstract]    
Difference (296) (381)
Distressed at Fair Value [Member]    
Loans, fair value [Abstract]    
Current through 89 days delinquent 423 445
90 or more days delinquent, not in foreclosure 1,242 1,421
90 or more days delinquent, in foreclosure 189 0
Fair value 1,854 1,866
Loans, principal amount due upon maturity [Abstract]    
Current through 89 days delinquent 567 595
90 or more days delinquent, not in foreclosure 3,245 3,796
90 or more days delinquent, in foreclosure 539 0
Principal amount due upon maturity 4,351 4,391
Loans, difference, [Abstract]    
Current through 89 days delinquent (144) (150)
90 or more days delinquent, not in foreclosure (2,003) (2,375)
90 or more days delinquent, in foreclosure (350) 0
Difference (2,497) (2,525)
Distressed at Fair Value [Member] | Nonperforming mortgage loans [Member]    
Loans, fair value [Abstract]    
Fair value 1,421
Loans, principal amount due upon maturity [Abstract]    
Principal amount due upon maturity 3,796
Loans, difference, [Abstract]    
Difference $ (2,353) $ (2,375)