Derivative Insturments and Hedging Activities - Part 4 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
IPL Regulatory Activity [Abstract]
(Increase) decrease in regulatory assets	$ 4	$ (4)	$ (1)	$ (6)
Increase (decrease) in regulatory liabilities	$ 0	$ (3)	$ (1)	$ 3

The change in regulatory liabilities resulting from the change in the fair value of derivative instruments accounted for in accordance with accounting standards for regulated operations.

No definition available.

Name:	aes_ChangeInRegulatoryLiabilityResultingFromChangeInDerivativeFairValue
Namespace Prefix:	aes_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration