Discontinued Operations And Held-For-Sale Businesses (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended					9 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Sonel [Member]	Sep. 30, 2013 Kribi [Member]	Sep. 30, 2013 Dibamba [Member]	Sep. 30, 2013 Cameroon [Member]	Sep. 30, 2013 Saurashtra [Member] MW	Apr. 29, 2013 Kiev and Rivne [Member] business	Jun. 30, 2013 Kiev and Rivne [Member]	Mar. 31, 2013 Kiev and Rivne [Member]	Apr. 29, 2013 Kiev [Member] customer	Apr. 29, 2013 Rivne [Member] customer
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Divestiture Of Ownership In Subsidiary Percent					56.00%	56.00%	56.00%						89.10%	84.60%
Asset Impairment Charges	$ 81	$ 43	$ 129	$ 71				$ 65	$ 12
Carrying Amount								262	19
Fair Value Less Costs To Sell								197	7
Generation capacity mega watts									39
Number of power distribution businesses sold										2
Net proceeds received from sale of businesses										113
Customers Served													881,000	412,000
(Gain) loss on disposal and impairment write-down - discontinued operations			(108)	130							3	(38)
Discontinued Operations Income Loss
Revenue	124	232	539	759
Income from operations of discontinued businesses, before income tax	24	32	27	33
Income tax benefit (expense)	2	(2)	(2)	(8)
Income from operations of discontinued businesses, after income tax	26	30	25	25
Net gain (loss) from disposal and impairments of discontinued businesses, after income tax	$ (78)	$ (2)	$ (111)	$ 68