Goodwill and Other Intangible Assets (Goodwill Roll Forward) (Details) (USD $)	12 Months Ended						12 Months Ended			12 Months Ended			12 Months Ended			12 Months Ended				3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 US	Dec. 31, 2012 US	Dec. 31, 2011 US	Dec. 31, 2013 Andes	Dec. 31, 2012 Andes	Dec. 31, 2011 Andes	Dec. 31, 2013 MCAC	Dec. 31, 2012 MCAC	Dec. 31, 2011 MCAC	Dec. 31, 2013 EMEA	Dec. 31, 2012 EMEA	Dec. 31, 2011 EMEA	Dec. 31, 2013 Asia	Dec. 31, 2012 Asia		Dec. 31, 2011 Asia	Sep. 30, 2011 Chigen	Sep. 30, 2011 Chigen Asia
Goodwill [Roll Forward]
Goodwill	$ 3,954,000,000	$ 3,959,000,000	$ 3,980,000,000	$ 2,658,000,000	$ 2,663,000,000	$ 2,672,000,000	$ 899,000,000	$ 899,000,000	$ 899,000,000	$ 149,000,000	$ 149,000,000	$ 149,000,000	$ 180,000,000	$ 180,000,000	$ 180,000,000	$ 68,000,000	$ 68,000,000		$ 80,000,000
Accumulated impairment losses	(2,332,000,000)	(1,960,000,000)	(160,000,000)	(2,152,000,000)	(1,838,000,000)	(21,000,000)	0	0	0	0	0	0	(180,000,000)	(122,000,000)	(122,000,000)	0	0		(17,000,000)
Net balance	1,999,000,000	3,820,000,000		825,000,000	2,651,000,000		899,000,000	899,000,000		149,000,000	149,000,000		58,000,000	58,000,000		68,000,000	63,000,000
Goodwill impairment expense	(372,000,000)	(1,817,000,000)	(17,000,000)	(314,000,000)	(1,817,000,000)		0	0		0	0		(58,000,000)	0		0	0			(17,000,000)	(17,000,000)
Goodwill acquired during the year		0			0			0			0			0			0	[1]
Goodwill associated with the sale of a business	0			0			0			0			0			0
Foreign currency translation and other	(5,000,000)	(4,000,000)		(5,000,000)	(9,000,000)		0	0		0	0		0	0		0	5,000,000
Net balance	1,622,000,000	1,999,000,000	3,820,000,000	506,000,000	825,000,000		899,000,000	899,000,000		149,000,000	149,000,000		0	58,000,000		68,000,000	68,000,000
Assets carrying amount																					$ 17,000,000

[1] Both the gross carrying amount and the accumulated impairment losses of the Asia generation segment have been reduced by $17 million with no impact on the net carrying amount for the segment. This relates to Chigen, which had fully impaired goodwill of $17 million and was sold during the year.