Goodwill and Other Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended					12 Months Ended		12 Months Ended		12 Months Ended												12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended					3 Months Ended	12 Months Ended										3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Land use rights [Member]	Dec. 31, 2011 Land use rights [Member]	Dec. 31, 2012 Water rights [Member]	Dec. 31, 2011 Water rights [Member]	Dec. 31, 2011 Trademark/Trade Name [Member]	Dec. 31, 2012 Trademark/Trade Name [Member]	Dec. 31, 2012 Other intangible assets	Dec. 31, 2011 Other intangible assets	Dec. 31, 2012 Project Development Rights [Member]	Dec. 31, 2011 Project Development Rights [Member]	Dec. 31, 2012 Sales Concessions [Member]	Dec. 31, 2011 Sales Concessions [Member]	Dec. 31, 2012 Contractuall Payment Rights [Member]	Dec. 31, 2011 Contractuall Payment Rights [Member]	Dec. 31, 2012 Management Rights [Member]	Dec. 31, 2011 Management Rights [Member]	Dec. 31, 2012 Emission allowances [Member]	Dec. 31, 2011 Emission allowances [Member]	Dec. 31, 2011 Electric security plan [Member]	Dec. 31, 2012 Electric security plan [Member]	Dec. 31, 2011 Contracts [Member]	Dec. 31, 2012 Contracts [Member]	Dec. 31, 2011 Customer relationships [Member]	Dec. 31, 2012 Customer relationships [Member]	Dec. 31, 2011 Other intangible assets [Member]	Dec. 31, 2012 Other intangible assets [Member]	Dec. 31, 2012 Renewable Energy Certificates [Member]	Dec. 31, 2011 DP&L [Member]	Dec. 31, 2011 DPL [Member]	Dec. 31, 2012 US Generation [Member]	Dec. 31, 2011 US Generation [Member]	Sep. 30, 2010 US Generation [Member] Deepwater [Member]	Dec. 31, 2012 US Utilities [Member]	Dec. 31, 2011 US Utilities [Member]	Dec. 31, 2012 Andes Generation [Member]	Dec. 31, 2011 Andes Generation [Member]	Dec. 31, 2012 MCAC Generation [Member]	Dec. 31, 2011 MCAC Generation [Member]	Dec. 31, 2012 EMEA Generation [Member]	Dec. 31, 2011 EMEA Generation [Member]	Dec. 31, 2012 Asia Generation [Member]	Dec. 31, 2011 Asia Generation [Member]	Sep. 30, 2011 Asia Generation [Member] Chigen [Member]	Dec. 31, 2012 Corporate Other And Other Eliminations [Member]	Dec. 31, 2011 Corporate Other And Other Eliminations [Member]
Goodwill [Roll Forward]
Goodwill	$ 3,980	$ 1,414																															$ 96	$ 106		$ 2,576	$ 0	$ 899	$ 899	$ 16	$ 16	$ 180	$ 180	$ 80	$ 80		$ 133	$ 133
Accumulated impairment losses	(160)	(143)																															(21)	(21)		0	0	0	0	0	0	(122)	(122)	(17)	0		0	0
Net balance	3,820	1,271																															75	85		2,576	0	899	899	16	16	58	58	63	80		133	133
Impairment losses	1,817	17	21																														0	0	18	(1,817)	0	0	0	0	0	0	0	0	(17)	17	0	0
Goodwill acquired during the year	0	2,576																													2,440	2,600	0	0		0	2,576	0	0	0	0	0	0	0	0		0	0
Goodwill associated with the sale of a business	0																																0			0		0		0		0		0			0
Foreign currency translation and other	(4)	(10)																															(9)	(10)		0	0	0	0	0	0	0	0	5	0		0	0
Goodwill	3,959	3,980	1,414																														87	96		2,576	2,576	899	899	16	16	180	180	68	80		133	133
Accumulated impairment losses	(1,960)	(160)	(143)																														(21)	(21)		(1,817)	0	0	0	0	0	(122)	(122)	0	(17)		0	0
Net balance	1,999	3,820	1,271																														66	75		759	2,576	899	899	16	16	58	58	68	63		133	133
Carrying Amount																																			18											17
Finite-Lived Intangible Assets [Line Items]
Gross Balance	624	645										102	109	194	199	72	69	40	39	4	14	87	87	44	44	66	66	18	15
Accumulated Amortization	276	164										(1)	(1)	(101)	(95)	(23)	(13)	(14)	(13)	0	0	(9)	(87)	(17)	(20)	(7)	(26)	(9)	(4)
Net Balance	348	481										101	108	93	104	49	56	26	26	4	14	78	0	27	24	59	40	9	11
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Estimated Amortization Expense 2013	32													8		9											11		4
Estimated Amortization Expense 2014	25													8		9											5		3
Estimated Amortization Expense 2015	24													8		9											4		3
Estimated Amortization Expense 2016	17													8		3											3		3
Estimated Amortization Expense 2017	16													8		3											3		2
Indefinite Lived Intangible Assets By Major Class Line Items
Indefinite-Lived Intangible Assets (Excluding Goodwill)	81	64		50	52	18	5	5	6	7	2
Acquired Finite-Lived Intangible Assets [Line Items]
Amount																						87		28		32		4		5
AcquiredIndefiniteLivedIntangibleAssetsLineItems
Amount						13		5		1
Intangible Assets Other Disclosures [Abstract]
Intangible Assets Gross Excluding Goodwill	705	709
Net Balance	429	545
Intangible asset amortization expense	$ 119	$ 36	$ 14
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Effective Income Tax Rate Continuing Operations	225.00%	29.00%	31.00%