Debt (Project Financing, Notes Payable and Others) (Details) - USD ($) $ in Millions |
Dec. 31, 2016 |
Dec. 31, 2015 |
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Debt Instrument [Line Items] | |||||||||||||
| Long-term Debt | $ 12,046 | $ 11,292 | |||||||||||
| Russell City Project [Member] | |||||||||||||
| Debt Instrument [Line Items] | |||||||||||||
| Long-term Debt | [1] | $ 462 | $ 522 | ||||||||||
| Debt Instrument, Interest Rate, Effective Percentage | [2] | 6.50% | 6.40% | ||||||||||
| Steamboat [Member] | |||||||||||||
| Debt Instrument [Line Items] | |||||||||||||
| Long-term Debt | [3] | $ 444 | $ 448 | ||||||||||
| Debt Instrument, Interest Rate, Effective Percentage | [2] | 5.40% | 6.80% | ||||||||||
| OMEC [Member] | |||||||||||||
| Debt Instrument [Line Items] | |||||||||||||
| Long-term Debt | $ 303 | $ 313 | |||||||||||
| Debt Instrument, Interest Rate, Effective Percentage | [2] | 7.20% | 7.10% | ||||||||||
| Los Esteros Project [Member] | |||||||||||||
| Debt Instrument [Line Items] | |||||||||||||
| Long-term Debt | $ 217 | $ 242 | |||||||||||
| Debt Instrument, Interest Rate, Effective Percentage | [2] | 3.70% | 3.10% | ||||||||||
| Pasadena [Member] | |||||||||||||
| Debt Instrument [Line Items] | |||||||||||||
| Long-term Debt | [4] | $ 91 | $ 107 | ||||||||||
| Debt Instrument, Interest Rate, Effective Percentage | [2] | 8.90% | 8.90% | ||||||||||
| Bethpage [Member] | |||||||||||||
| Debt Instrument [Line Items] | |||||||||||||
| Long-term Debt | [5] | $ 66 | $ 73 | ||||||||||
| Debt Instrument, Interest Rate, Effective Percentage | [2],[5] | 7.20% | 7.20% | ||||||||||
| Other Debt Obligations [Member] | |||||||||||||
| Debt Instrument [Line Items] | |||||||||||||
| Long-term Debt | $ 14 | $ 10 | |||||||||||
| Debt Instrument, Interest Rate, Effective Percentage | [2] | 0.00% | 0.00% | ||||||||||
| Project Financing Total [Member] | |||||||||||||
| Debt Instrument [Line Items] | |||||||||||||
| Long-term Debt | $ 1,597 | $ 1,715 | |||||||||||
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