v3.26.1
Mortgage Loans - Loan Restructuring - Subsequent Default (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default $ 2,218 $ 2,014
Payment Delay as a Result of a Payment Deferral (Only)    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 1,096 1,228
Payment Delay and Term Extension    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 1,025 763
Payment Delay, Term Extension, Interest Rate Reduction, and Other    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 97 23
Single-family    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 2,218 2,014
Single-family | Payment Delay as a Result of a Payment Deferral (Only)    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 1,096 1,228
Single-family | Payment Delay and Term Extension    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 1,025 763
Single-family | Payment Delay, Term Extension, Interest Rate Reduction, and Other    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 97 23
Single-family | 20- and 30-year or more, amortizing fixed-rate    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 2,155 1,951
Single-family | 20- and 30-year or more, amortizing fixed-rate | Payment Delay as a Result of a Payment Deferral (Only)    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 1,053 1,176
Single-family | 20- and 30-year or more, amortizing fixed-rate | Payment Delay and Term Extension    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 1,009 756
Single-family | 20- and 30-year or more, amortizing fixed-rate | Payment Delay, Term Extension, Interest Rate Reduction, and Other    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 93 19
Single-family | 15-year or less, amortizing fixed-rate    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 39 34
Single-family | 15-year or less, amortizing fixed-rate | Payment Delay as a Result of a Payment Deferral (Only)    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 28 34
Single-family | 15-year or less, amortizing fixed-rate | Payment Delay and Term Extension    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 10 0
Single-family | 15-year or less, amortizing fixed-rate | Payment Delay, Term Extension, Interest Rate Reduction, and Other    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 1 0
Single-family | Adjustable-rate    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 4 6
Single-family | Adjustable-rate | Payment Delay as a Result of a Payment Deferral (Only)    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 4 5
Single-family | Adjustable-rate | Payment Delay and Term Extension    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 0 0
Single-family | Adjustable-rate | Payment Delay, Term Extension, Interest Rate Reduction, and Other    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 0 1
Single-family | Other    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 20 23
Single-family | Other | Payment Delay as a Result of a Payment Deferral (Only)    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 11 13
Single-family | Other | Payment Delay and Term Extension    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 6 7
Single-family | Other | Payment Delay, Term Extension, Interest Rate Reduction, and Other    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 3 3
Multifamily    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 0 0
Multifamily | Payment Delay as a Result of a Payment Deferral (Only)    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 0 0
Multifamily | Payment Delay and Term Extension    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default 0 0
Multifamily | Payment Delay, Term Extension, Interest Rate Reduction, and Other    
Loans in Mortgage Portfolio [Line Items]    
Restructured loans, amortized cost, subsequent default $ 0 $ 0