Commitments and Contingencies (Narrative) (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Oct. 31, 2009 coal_fired_electric_generating_facility	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Entity Information [Line Items]
Issued Guarantees		$ 226,200
Coal, Gas, Purchased Power and Related Transportation Purchase Obligations, Net		1,241,800
Other Purchase Obligations, Net		321,200
Coal, Gas, Purchased Power and Related Transportation Purchase Obligations Less Than 1 Year		280,600
Coal, Gas, Purchased Power and Related Transportation Purchase Obligations in Years 1 through 3		310,300
Coal, Gas, Purchased Power and Related Transportation Purchase Obligations Years 3 through 5		234,300
Coal, Gas, Purchased Power and Related Transportation Purchase Obligations After Year 5		416,600
Other Purchase Obligations, After Year 5		7,700
Other Purchase Obligations Years 3 through 5		14,600
Other Purchase Obligations Years 1 through 3		57,300
Other Purchase Obligations Less than 1 Year		241,600
Loss contingencies accrued			$ 13,400
Probable Insurance Recoveries Receivables		12,500	11,300
Other Assets, Noncurrent		873,923	498,658
Prepaid Implementation Costs for Software as a Service
Entity Information [Line Items]
Other Assets, Noncurrent		9,100	8,800
Indianapolis Power And Light Company
Entity Information [Line Items]
Number of facilities with violations of Federal Clean Air Act | coal_fired_electric_generating_facility	3
Issued Guarantees		226,200
Coal, Gas, Purchased Power and Related Transportation Purchase Obligations, Net		1,241,800
Other Purchase Obligations, Net		321,200
Coal, Gas, Purchased Power and Related Transportation Purchase Obligations Less Than 1 Year		280,600
Coal, Gas, Purchased Power and Related Transportation Purchase Obligations in Years 1 through 3		310,300
Coal, Gas, Purchased Power and Related Transportation Purchase Obligations Years 3 through 5		234,300
Coal, Gas, Purchased Power and Related Transportation Purchase Obligations After Year 5		416,600
Other Purchase Obligations, After Year 5		7,700
Other Purchase Obligations Years 3 through 5		14,600
Other Purchase Obligations Years 1 through 3		57,300
Other Purchase Obligations Less than 1 Year		241,600
Loss contingencies accrued		200	15,400
Probable Insurance Recoveries Receivables		12,500	11,300
Other Assets, Noncurrent		870,212	495,328
Indianapolis Power And Light Company | Prepaid Implementation Costs for Software as a Service
Entity Information [Line Items]
Other Assets, Noncurrent		$ 9,100	$ 8,800