Contingencies and Commitments (Details)			3 Months Ended									6 Months Ended		12 Months Ended
	Jun. 30, 2011 USD ($)	Dec. 31, 2010 USD ($)	Jun. 30, 2011 Guarantees USD ($)	Jun. 30, 2011 Letters of credit under secured credit facility USD ($)	Jun. 30, 2011 Cash Collateralized Letters Of Credit [Member] USD ($)	Jun. 30, 2011 Eletropaulo Member USD ($)	Jun. 30, 2011 Eletropaulo Member BRL	Jun. 30, 2011 CESCO Member USD ($)	Jun. 30, 2011 Itabo Member USD ($)	Jun. 30, 2011 Nurenergoservice Member USD ($)	Jun. 30, 2011 Nurenergoservice Member KZT	Jun. 30, 2009 Cartagena Affiliate [Member] USD ($)	Jun. 30, 2009 Cartagena Affiliate [Member] EUR (€)	Dec. 31, 2008 Cartagena Affiliate [Member] USD ($)	Dec. 31, 2008 Cartagena Affiliate [Member] EUR (€)	Dec. 31, 2007 Cartagena Affiliate [Member] USD ($)	Dec. 31, 2007 Cartagena Affiliate [Member] EUR (€)	Jun. 30, 2011 Cartagena Affiliate [Member] USD ($)	Jun. 30, 2011 Cartagena Affiliate [Member] EUR (€)	Jun. 30, 2011 UKHPP Member USD ($)	Jun. 30, 2011 UKHPP Member KZT	Jun. 30, 2011 Maritza [Member] USD ($)	Jun. 30, 2011 Maritza [Member] EUR (€)	Jun. 30, 2011 Shulbinsk [Member] USD ($)	Jun. 30, 2011 Shulbinsk [Member] KZT
Environmental Contingencies Disclosure Abstract
Liability recorded for projected environmental remediation costs	$ 26,000,000
Estimated Annual Cost Of Environmental Compliance	15,000,000
Guarantees Letters Of Credit Abstract
Obligations made by the Parent Company associated with non-recourse debt	27,000,000
Contingent Contractual Obligations [Line Items]
Amount	415,000,000		362,000,000	26,000,000	27,000,000
Number of Agreements	45		23	11	11
Maximum Exposure Range for Each Agreement			<$1 - $53	<$1 - $16	<$1 - $15
Commitments to invest in subsidiaries, excluding letters of credit	45,000,000
Commitment to purchase DPL	3,500,000,000
Litigation Contingency Disclosure Abstract
Aggregate reserves for claims deemed both probable and reasonably estimable	493,000,000	448,000,000
Loss Contingency Range Of Possible Loss Maximum	1,900,000,000
Litigation Details [Line Items]
Litigation Collection Suit Alleged Amount						765,000,000	1,200,000,000
Arbitration Alleged Damages Amount								189,000,000
Litigation Alleged Damages									15,000,000	123,000,000	18,000,000,000
Litigation Alleged Damages Seized										5,000,000	778,000,000
Litigation Alleged Fines										12,000,000	1,800,000,000									1,000,000	120,000,000
Litigation Disgorge Of Profits																				3,000,000	440,000,000
Litigation Pollution Liability Amount						467,000,000	733,000,000
Litigation Notified Invoice Amount																		29,000,000	20,000,000
Litigation Invoiced Amount												7,000,000	5,000,000	29,000,000	19,907,248	753,000	523,548
Litigation Allowances Paid To Date																		36,000,000	25,000,000
Amount Demanded Under Performance Bond																						223,000,000	155,000,000
Increase To Contract Price Demanded																						89,000,000	62,000,000
Litigation Additional Damages																				8,000,000	1,200,000,000			9,000,000	1,300,000,000
Additional Damages Sought																						$ 14,000,000	€ 10,000,000