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Acquisitions, Divestitures and Discontinued Operations (Acquisition of Broad River and South Point Leases) (Details) (USD $) In Millions, unless otherwise specified | Dec. 08, 2010 | Jul. 02, 2010
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Broad River and South Point Leases [Line Items] |  |
Broad River: debt extinguishment costs | $ 30 |
South Point: impairment loss | 95 |
Total loss recorded for this transaction | 125 |
Acquisition of Broad River and South Point Leases (Textuals) [Abstract] |  |
Business Acquisition, Purchase Price Allocation, Notes Payable and Long-term Debt | 297 |
Business Acquisition, Cost of Acquired Entity, Cash Paid | 40 |
Business Acquisition, Purchase Price Allocation, Liabilities Assumed | 85 | 97
Debt Eliminated In Acquisition | $ (212) |

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