Derivative Instruments (Details 4) (Details) - USD ($) $ in Millions |
12 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
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| Derivative Instruments, Gain (Loss) [Line Items] | |||||||||||
| Gain (loss) on cash flow hedges before reclassification adjustment for cash flow hedges realized in net income (loss) | $ (2) | $ (6) | $ (48) | ||||||||
| Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax | (40) | 46 | 26 | ||||||||
| Interest Rate Contract [Member] | |||||||||||
| Derivative Instruments, Gain (Loss) [Line Items] | |||||||||||
| Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax | [1],[2] | (41) | 45 | 21 | |||||||
| Depreciation expense [Member] | |||||||||||
| Derivative Instruments, Gain (Loss) [Line Items] | |||||||||||
| Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax | [1],[2] | 1 | 1 | 5 | |||||||
| Reclassification out of Accumulated Other Comprehensive Income [Member] | |||||||||||
| Derivative Instruments, Gain (Loss) [Line Items] | |||||||||||
| Gain (loss) on cash flow hedges before reclassification adjustment for cash flow hedges realized in net income (loss) | (2) | (6) | (48) | ||||||||
| Reclassification out of Accumulated Other Comprehensive Income [Member] | Interest Rate Contract [Member] | |||||||||||
| Derivative Instruments, Gain (Loss) [Line Items] | |||||||||||
| Gain (loss) on cash flow hedges before reclassification adjustment for cash flow hedges realized in net income (loss) | [1],[2],[3],[4] | (1) | (5) | (43) | |||||||
| Reclassification out of Accumulated Other Comprehensive Income [Member] | Depreciation expense [Member] | |||||||||||
| Derivative Instruments, Gain (Loss) [Line Items] | |||||||||||
| Gain (loss) on cash flow hedges before reclassification adjustment for cash flow hedges realized in net income (loss) | [1],[2],[3],[4] | $ (1) | $ (1) | $ (5) | |||||||
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