Financial Guarantees (Details) - USD ($) $ in Millions |
6 Months Ended | |
|---|---|---|
Jun. 30, 2025 |
Dec. 31, 2024 |
|
| Financial Guarantees and Maximum Recovery [Line Items] | ||
| Contractual terms of our guarantees | 29 years | |
| Maximum Exposure | $ 11,373 | $ 11,398 |
| Guaranty Obligation | 64 | 69 |
| Maximum recovery | 4,365 | 4,386 |
| Unconsolidated Fannie Mae MBS | Unconsolidated VIEs | ||
| Financial Guarantees and Maximum Recovery [Line Items] | ||
| Maximum Exposure | 2,365 | 2,484 |
| Guaranty Obligation | 13 | 13 |
| Maximum recovery | 2,319 | 2,432 |
| Other guaranty arrangements | Unconsolidated VIEs | ||
| Financial Guarantees and Maximum Recovery [Line Items] | ||
| Maximum Exposure | 9,008 | 8,914 |
| Guaranty Obligation | 51 | 56 |
| Maximum recovery | 2,046 | 1,954 |
| Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise | Unconsolidated VIEs | ||
| Financial Guarantees and Maximum Recovery [Line Items] | ||
| Single security, Freddie Mac issued securities backing unconsolidated Fannie Mae securities | $ 192,200 | $ 200,100 |