v2.4.0.8

Acquisitions, Divestitures and Discontinued Operations (Textuals) (Details) (USD $) In Millions, unless otherwise specified | 3 Months Ended | 12 Months Ended |  |  | 12 Months Ended |
--- | --- | --- | --- | --- | --- | ---
Dec. 31, 2013 MW | Dec. 31, 2013 MW | Dec. 31, 2012 MW | Dec. 31, 2011 | Dec. 31, 2013 Guadalupe Energy Center [Member] MW | Dec. 31, 2013 Guadalupe Expansion Capacity [Member] MW | Dec. 31, 2012 Bosque Energy Center [Member] MW | Dec. 31, 2012 Riverside Energy Center [Member] MW | Dec. 31, 2012 Broad River Energy Center [Member] MW | Dec. 27, 2012 Broad River Energy Center [Member]
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Power generation capacity | 9,027 | 9,027 | 8,255 |  | 1,050 | 400 | 800 | 603 | 847 |
Proceeds from Sale of Productive Assets |  |  |  |  |  |  |  | $ 402 | $ 423 |
Number of 525 MW generation blocks to be acquired in the Guadalupe acquisition | 2 |  |  |  |  |  |  |  |  |
Business Acquisition, Purchase Price Allocation, Assets Acquired |  |  |  |  | 625 | 15 | 432 |  |  |
Block one power generation capacity |  |  |  |  |  |  | 250 |  |  |
Block two power generation capacity |  |  |  |  |  |  | 550 |  |  |
Gain (Loss) on Disposition of Assets |  | $ 0 | $ 222 | $ 0 |  |  |  | $ 7 | $ 215 |
Ownership percentage before divestiture of business |  |  |  |  |  |  |  |  |  | 100.00%

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