Sales Of Oatsville Coal Reserve (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended		1 Months Ended
	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010 Indianapolis Power And Light Company [Member]	Dec. 31, 2010 Indianapolis Power And Light Company [Member]
Sale of land	$ 13.5		$ 13.5
Carrying value of the land held for sale		0.2		0.2
Gain on sale of land	$ 13.3		$ 13.3