Debt (Letter of Credit) (Details) - USD ($) $ in Millions |
Jun. 30, 2020 |
Dec. 31, 2019 |
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|---|---|---|---|---|---|---|---|---|---|---|
| Line of Credit Facility [Line Items] | ||||||||||
| Letters of Credit Outstanding, Amount | $ 1,076 | $ 1,085 | ||||||||
| Revolving facilities | ||||||||||
| Line of Credit Facility [Line Items] | ||||||||||
| Letters of Credit Outstanding, Amount | [1] | 462 | 604 | |||||||
| CDHI | ||||||||||
| Line of Credit Facility [Line Items] | ||||||||||
| Letters of Credit Outstanding, Amount | [2] | 3 | 3 | |||||||
| Various project financing facilities(2) | ||||||||||
| Line of Credit Facility [Line Items] | ||||||||||
| Letters of Credit Outstanding, Amount | [3] | 336 | 184 | |||||||
| Other corporate facilities | ||||||||||
| Line of Credit Facility [Line Items] | ||||||||||
| Letters of Credit Outstanding, Amount | [4] | $ 275 | $ 294 | |||||||
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