Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 1,455,300	$ 1,428,900
REVENUES	1,481,643	1,450,505	$ 1,349,588
Contract with Customer, Asset, Gross	155,000			$ 160,800
Retail Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,375,533	1,380,042
Other non-606 revenue	23,841	16,423
Wholesale Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	68,474	38,789
Miscellaneous revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	11,335	10,057
Other non-606 revenue	2,460	5,194
Electricity [Member]
Disaggregation of Revenue [Line Items]
REVENUES	1,481,643	1,450,505
Indianapolis Power And Light Company
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,455,300	1,428,900
REVENUES	1,481,643	1,450,505	$ 1,349,588
Contract with Customer, Asset, Gross	155,000			$ 160,800
Indianapolis Power And Light Company | Retail Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,375,533	1,380,042
Other non-606 revenue	23,841	16,423
Indianapolis Power And Light Company | Wholesale Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	68,474	38,789
Indianapolis Power And Light Company | Miscellaneous revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	11,335	10,057
Other non-606 revenue	2,460	5,194
Indianapolis Power And Light Company | Electricity [Member]
Disaggregation of Revenue [Line Items]
REVENUES	$ 1,481,643	$ 1,450,505