Other Income and Expense (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Component Of Other Income [Line Items]
Total other income	$ 105	$ 149	$ 100
Net impact of Eletropaulo swap liability gain after tax and noncontrolling interests			9
Component Of Operating Other Cost And Expense [Line Items]
Total other expense	93	153	232
Gains Losses On Extinguishment Of Debt	(7)	(62)	(34)
Loss On Sale And Disposal Of Assets [Member]
Component Of Operating Other Cost And Expense [Line Items]
Total other expense	64	68	84
Loss On Extinguishment Of Debt [Member]
Component Of Operating Other Cost And Expense [Line Items]
Total other expense	8	62	37
Other Member
Component Of Operating Other Cost And Expense [Line Items]
Total other expense	21	23	17
Gas Settlement [Member]
Component Of Operating Other Cost And Expense [Line Items]
Total other expense	0	0	72
Transaction Costs Written Off [Member]
Component Of Operating Other Cost And Expense [Line Items]
Total other expense	0	0	22
Parent Company | Retirement Of Senior Notes [Member]
Component Of Operating Other Cost And Expense [Line Items]
Total other expense			15
Gener Subsidiary [Member] | Loss On Extinguishment Of Debt [Member]
Component Of Operating Other Cost And Expense [Line Items]
Total other expense		36
Gener Subsidiary [Member] | Gas Settlement [Member]
Component Of Operating Other Cost And Expense [Line Items]
Total other expense			72
Andres And Itabo [Member] | Loss On Extinguishment Of Debt [Member]
Component Of Operating Other Cost And Expense [Line Items]
Total other expense			18
IPL Subsidiary [Member] | Retirement Of Senior Notes [Member]
Component Of Operating Other Cost And Expense [Line Items]
Total other expense		15
Eletropaulo and TermoAndes [Member] | Loss On Sale And Disposal Of Assets [Member]
Component Of Operating Other Cost And Expense [Line Items]
Total other expense		68
Eletropualo, Panama, and Gener [Member] | Loss On Sale And Disposal Of Assets [Member]
Component Of Operating Other Cost And Expense [Line Items]
Total other expense			84
Wind Generation Business [Member] | Transaction Costs Written Off [Member]
Component Of Operating Other Cost And Expense [Line Items]
Total other expense			22
Tax Credit Settlement [Member]
Component Of Other Income [Line Items]
Total other income	0	31	0
Extinguishment Of Liability [Member] | Brazilian Subsidiaries [Member]
Component Of Other Income [Line Items]
Total other income			62
Gain on sale of assets
Component Of Other Income [Line Items]
Total other income	21	47	12
Insurance Proceeds [Member]
Component Of Other Income [Line Items]
Total other income	40	11	1
Other Income Other [Member]
Component Of Other Income [Line Items]
Total other income	44	46	25
Gain On Extinguishment Of Tax And Other Liabilities [Member]
Component Of Other Income [Line Items]
Total other income	$ 0	$ 14	$ 62