Discontinued Operations And Held-For-Sale Businesses (Details) (USD $)	3 Months Ended						7 Months Ended		0 Months Ended		0 Months Ended		1 Months Ended
	Mar. 31, 2014	Mar. 31, 2013		Sep. 30, 2013 Sonel [Member]	Sep. 30, 2013 Kribi [Member]	Sep. 30, 2013 Dibamba [Member]	Mar. 31, 2014 Cameroon [Member]	Sep. 30, 2013 Cameroon [Member]	Feb. 24, 2014 Saurashtra [Member]	Oct. 30, 2013 Saurashtra [Member] MW	Jan. 30, 2014 US Wind Projects [Member]	Nov. 30, 2013 US Wind Projects [Member] project MW	Nov. 30, 2013 Armenia Mountain [Member] MW
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Sale of ownership in subsidiary percent				56.00%	56.00%	56.00%						100.00%
Asset impairment charges	$ 166,000,000	$ 48,000,000					$ 101,000,000
Carrying amount								435,000,000
Fair value less costs to sell								334,000,000
Generation capacity mega watts										39		234	101
Net proceeds received from sale of businesses									8,000,000		27,000,000
Number of wind projects												3
Buyer option to purchase ownership interest, sales price													75,000,000
Buyer option to purchase ownership percent													100.00%
Deferred proceeds from divestiture of businesses											3,000,000
Discontinued Operations Income Loss
Revenue	129,000,000	262,000,000	[1]
Income from operations of discontinued businesses, before income tax	34,000,000	2,000,000	[1]
Income tax benefit (expense)	(14,000,000)	2,000,000	[1]
Income from operations of discontinued businesses, after income tax	20,000,000	4,000,000	[1]
Net loss from disposal and impairments of discontinued businesses, after income tax	$ (43,000,000)	$ (36,000,000)	[1]

[1] Includes the results of operations of our Ukraine utility businesses, which were sold in April 2013.