v3.26.1
Relationship with BLG and Bayview Financial (Detail) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Schedule of Equity Method Investments [Line Items]          
Revenue from contract with customer $ 442,000,000 $ 417,000,000 $ 860,000,000 $ 814,000,000  
Deposits 168,885,000,000   168,885,000,000   $ 166,909,000,000
Bayview Financial          
Schedule of Equity Method Investments [Line Items]          
Deposits $ 4,700,000,000   $ 4,700,000,000   3,500,000,000
Bayview Lending Group          
Schedule of Equity Method Investments [Line Items]          
Ownership percentage (as a percent) 20.00%   20.00%    
Equity method investments $ 0   $ 0    
Bayview Lending Group | Income Statement Location: us-gaap:NoninterestIncomeOtherOperatingIncome          
Schedule of Equity Method Investments [Line Items]          
Income from equity method investments 47,000,000 0 80,000,000 0  
Bayview Lending Group and Bayview Financial          
Schedule of Equity Method Investments [Line Items]          
Outstanding principal balances of mortgage servicing rights 819,000,000   819,000,000   875,000,000
Bayview Financial          
Schedule of Equity Method Investments [Line Items]          
Outstanding principal balances of residential mortgage loans from Bayview Financial 183,600,000,000   183,600,000,000   156,900,000,000
Revenues from sub-servicing 68,000,000 $ 56,000,000 131,000,000 $ 97,000,000  
Investment securities in held-to-maturity portfolio securitized by Bayview Financial 28,000,000   28,000,000   32,000,000
Commitments to extend credit 929,000,000   929,000,000    
Outstanding balance $ 764,000,000   $ 764,000,000   $ 635,000,000