|
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% | |||||||||