Commitments and Contingencies (Details) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Oct. 31, 2009 coal_fired_electric_generating_facility	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Entity Information [Line Items]
Payment of Civil Penalties		$ 1,525
Environmental Mitigation Project Costs		5,000
Environmentally Beneficial Project Expenditure		325
Total Legal Loss Contingencies Accrued		$ 13,400	$ 13,400
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Number of facilities with violations of Federal Clean Air Act | coal_fired_electric_generating_facility	3