Goodwill and Intangible Assets (Intangible Assets by Business Segment) (Details) - USD ($) $ in Millions |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|---|---|---|---|
| Intangible Assets | |||
| Amortizable intangibles | $ 2,158 | $ 2,445 | $ 2,718 |
| Mortgage servicing rights | 5 | 3 | |
| Intangible assets | 2,163 | 2,448 | |
| IS | |||
| Intangible Assets | |||
| Amortizable intangibles | 270 | 349 | 346 |
| Mortgage servicing rights | 2 | 0 | |
| Intangible assets | 272 | 349 | |
| WM | |||
| Intangible Assets | |||
| Amortizable intangibles | 1,828 | 2,092 | 2,361 |
| Mortgage servicing rights | 3 | 3 | |
| Intangible assets | 1,831 | 2,095 | |
| IM | |||
| Intangible Assets | |||
| Amortizable intangibles | 60 | 4 | $ 11 |
| Mortgage servicing rights | 0 | 0 | |
| Intangible assets | $ 60 | $ 4 |