v3.26.1
Mortgage Loans Held for Portfolio Credit Quality Indicators (Details) - Residential Portfolio Segment [Member] - Conventional Mortgage Loan [Member] - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Financing Receivable, Credit Quality Indicator [Line Items]    
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year [1] $ 66 $ 71
Financial Asset, 30 to 59 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year 1 2
Financial Asset, 60 to 89 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year 1 1
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year 1 1
Financial Asset, Past Due    
Financing Receivable, Credit Quality Indicator [Line Items]    
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year 3 4
Financial Asset, Not Past Due    
Financing Receivable, Credit Quality Indicator [Line Items]    
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year $ 63 $ 67
[1] Amortized cost excludes accrued interest receivable that was not material for the reported periods.