Commitments, Contingencies and Guarantees (Narrative) (Details) - USD ($) $ in Millions |
Mar. 31, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Long-term Purchase Commitment [Line Items] | ||
| Fannie Mae DUS Servicing Portfolio, Amount | $ 7,900 | $ 7,800 |
| Fannie Mae Servicing Portfolio, Other, Amount | 881 | 823 |
| Maximum Quantifiable Fannie Mae Loss Share Guarantee | $ 2,900 | $ 2,700 |