Derivative Instruments (Details 5) (Details) - USD ($) $ in Millions |
3 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Mar. 31, 2019 |
Mar. 31, 2018 |
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| Derivative Instruments, Gain (Loss) [Line Items] | |||||||||||
| Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax | $ (25) | $ 55 | |||||||||
| Reclassification adjustment for loss on cash flow hedges realized in net income (loss) | [1],[2] | 2 | (7) | ||||||||
| Depreciation expense [Member] | |||||||||||
| Derivative Instruments, Gain (Loss) [Line Items] | |||||||||||
| Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax | [3],[4] | 0 | 1 | ||||||||
| Reclassification adjustment for loss on cash flow hedges realized in net income (loss) | [1],[2],[3],[4] | 0 | (1) | ||||||||
| Interest Rate Hedging Instruments | |||||||||||
| Derivative Instruments, Gain (Loss) [Line Items] | |||||||||||
| Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax | [3],[4] | (25) | 54 | ||||||||
| Reclassification adjustment for loss on cash flow hedges realized in net income (loss) | [1],[2],[3],[4] | $ 2 | $ (6) | ||||||||
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