Goodwill and Intangible Assets (Net Amortizable Intangible Assets Rollforward) (Details) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Amortizable Intangible Assets | ||
| Beginning balance | $ 2,445 | $ 2,718 |
| Acquired | 66 | 51 |
| Disposals | (6) | (15) |
| Amortization expense | (344) | (309) |
| Other | (3) | |
| Ending balance | 2,158 | 2,445 |
| IS | ||
| Amortizable Intangible Assets | ||
| Beginning balance | 349 | 346 |
| Acquired | 0 | 51 |
| Disposals | (6) | (15) |
| Amortization expense | (70) | (33) |
| Other | (3) | |
| Ending balance | 270 | 349 |
| WM | ||
| Amortizable Intangible Assets | ||
| Beginning balance | 2,092 | 2,361 |
| Acquired | 0 | 0 |
| Disposals | 0 | 0 |
| Amortization expense | (264) | (269) |
| Other | 0 | |
| Ending balance | 1,828 | 2,092 |
| IM | ||
| Amortizable Intangible Assets | ||
| Beginning balance | 4 | 11 |
| Acquired | 66 | 0 |
| Disposals | 0 | 0 |
| Amortization expense | (10) | (7) |
| Other | 0 | |
| Ending balance | $ 60 | $ 4 |