Assets and Liabilities Held for Sale - Narrative (Details) - USD ($) $ in Millions |
1 Months Ended | 12 Months Ended | |
|---|---|---|---|
Jan. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] | |||
| Impairment loss | $ 197 | $ 57 | |
| Lion City Rentals | Not Discontinued Operations | |||
| Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] | |||
| Equity percentage to be purchased | 100.00% | ||
| Fair value of consideration received, cash | $ 310 | ||
| Contingent consideration | $ 33 | ||