v3.26.1
Fair Value - Key Assumptions Used in Determining Fair Value of MSRs at Time of Initial Recognition (Detail)
$ in Thousands
 3 Months Ended
Mar. 31, 2026
USD ($)
UsdPerLoan
Mar. 31, 2025
USD ($)
UsdPerLoan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value, MSR recognized | $ $ 40,281 $ 47,009
Fair value, Unpaid principal balance of underlying loans | $ $ 2,197,665 $ 2,594,638
Fair value, Weighted-average annual servicing fee rate (in basis points) 0.34% 0.32%
Minimum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value inputs, Pricing spread during period 5.20% 5.20%
Fair Value inputs, Prepayment speed during period 8.60% 9.40%
Fair Value inputs, Weighted average equivalent average life during period 3 years 8 months 12 days 3 years 8 months 12 days
Fair Value inputs, Annual per loan cost of servicing during period 69 68
Maximum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value inputs, Pricing spread during period 10.00% 7.30%
Fair Value inputs, Prepayment speed during period 14.90% 15.30%
Fair Value inputs, Weighted average equivalent average life during period 8 years 8 months 12 days 8 years 2 months 12 days
Fair Value inputs, Annual per loan cost of servicing during period 113 87
Weighted Average [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value inputs, Pricing spread during period 6.20% 5.50%
Fair Value inputs, Prepayment speed during period 9.40% 9.90%
Fair Value inputs, Weighted average equivalent average life during period 8 years 2 months 12 days 7 years 10 months 24 days
Fair Value inputs, Annual per loan cost of servicing during period 72 69