Property, Plant and Equipment (Schedule Of Original Cost Of Utility Plant In Service) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Entity Information [Line Items]
Production	$ 4,154,919	$ 3,927,847
Transmission	398,903	394,621
Distribution	1,594,208	1,533,828
General plant	250,582	344,782
Total utility plant in service	6,398,612	6,201,078
Indianapolis Power And Light Company
Entity Information [Line Items]
Production	4,154,919	3,927,847
Transmission	398,903	394,621
Distribution	1,594,208	1,533,828
General plant	250,582	344,782
Total utility plant in service	$ 6,398,612	$ 6,201,078