Debt - Non-Recourse Debt Narrative (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Debt Instrument [Line Items]
Loss on extinguishment of debt	$ (122)	$ 23	$ (15)	$ (145)	$ (149)
Nonrecourse Debt [Member] | Gener Subsidiary [Member]
Debt Instrument [Line Items]
Issued new debt	150			150
Nonrecourse Debt [Member] | Sul Subsidiary [Member]
Debt Instrument [Line Items]
Issued new debt	499			499
Repayments of Debt				468
Nonrecourse Debt [Member] | IPALCO Enterprises, Inc. [Member]
Debt Instrument [Line Items]
Issued new debt	405			405
Repayments of Debt				384
Nonrecourse Debt [Member] | PANAMA
Debt Instrument [Line Items]
Issued new debt	300			300
Repayments of Debt				287
Nonrecourse Debt [Member] | Cochrane Subsidiary [Member]
Debt Instrument [Line Items]
Issued new debt	297			297
Nonrecourse Debt [Member] | Eletropaulo [Domain]
Debt Instrument [Line Items]
Issued new debt	118			118
Nonrecourse Debt [Member] | Mong Duong Subsidiary [Member]
Debt Instrument [Line Items]
Issued new debt	$ 104			$ 104