v3.26.1
Fair Value - Level 3 Valuation Inputs (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Fair Value Inputs, Quantitative Information [Line Items]    
Available-for-sale securities $ 12,424 $ 375
Net derivatives 314 133
Recurring    
Fair Value Inputs, Quantitative Information [Line Items]    
Trading securities 63,096 69,514
Available-for-sale securities 12,424 375
Significant Unobservable Inputs (Level 3)    
Fair Value Inputs, Quantitative Information [Line Items]    
Trading securities 26 27
Available-for-sale securities 331 341
Significant Unobservable Inputs (Level 3) | Recurring    
Fair Value Inputs, Quantitative Information [Line Items]    
Trading securities 26 27
Available-for-sale securities 331 341
Significant Unobservable Inputs (Level 3) | Recurring | Dealer Mark and Discounted Cash Flow    
Fair Value Inputs, Quantitative Information [Line Items]    
Net derivatives 54 65
Mortgage-related securities | Recurring    
Fair Value Inputs, Quantitative Information [Line Items]    
Trading securities 18,672 14,291
Available-for-sale securities 518 375
Mortgage-related securities | Significant Unobservable Inputs (Level 3) | Recurring    
Fair Value Inputs, Quantitative Information [Line Items]    
Trading securities 26 27
Available-for-sale securities 331 341
Mortgage-related securities | Significant Unobservable Inputs (Level 3) | Recurring | Single Vendor    
Fair Value Inputs, Quantitative Information [Line Items]    
Trading securities 26 27
Mortgage-related securities | Significant Unobservable Inputs (Level 3) | Recurring | Primarily Consensus, Single Vendor, and Discounted Cash Flow    
Fair Value Inputs, Quantitative Information [Line Items]    
Available-for-sale securities $ 331 $ 341