Mortgage Servicing Assets - Changes in Carrying Amount of Mortgage Servicing Assets (Details) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Agency commercial mortgage-backed securities | ||
| Servicing Asset at Amortized Cost, Balance [Roll Forward] | ||
| Balance at beginning of period | $ 609 | $ 638 |
| Servicing retained from loan sales | 83 | 67 |
| Purchases | 11 | 28 |
| Amortization | (125) | (124) |
| Balance at end of period | 578 | 609 |
| Fair value at end of period | 736 | 819 |
| Agency residential mortgage-backed securities | ||
| Servicing Asset at Amortized Cost, Balance [Roll Forward] | ||
| Balance at beginning of period | 111 | 108 |
| Servicing retained from loan sales | 14 | 13 |
| Amortization | (12) | (11) |
| Temporary recoveries (impairments) | 0 | 1 |
| Balance at end of period | 113 | 111 |
| Fair value at end of period | $ 137 | $ 138 |