Other Income and Expense (Nonoperating Income) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of assets	$ 68	$ 12	$ 21
Contingency reversal	18	10	0
Contract termination - Beaver Valley	0	60	0
Insurance proceeds	0	0	38
Gain on extinguishment of tax and other liabilities	0	9	0
Other	38	34	39
Total other income	124	125	98
AES Cartagena
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of assets	54
ARGENTINA
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Interest Income, Other				59
Embedded Derivative, Gain on Embedded Derivative				$ 106