Related Party Transactions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Self-insured retention per occurrence	$ 5.0
Insurance expense	7.0	$ 5.6	$ 4.3
Prepaid insurance			2.3	$ 2.3
Health coverage expense	23.7	21.0	20.2
Income taxes receivable	15.6	24.4
Deferred Compensation Arrangement with Individual, Compensation Expense	0.2	0.3	0.3
Billings from related party			4.3	6.5	$ 3.0
Parent Loan Repayment	6.1
Contract with Customer, Liability	0.0	0.5
Service Company [Member]
Related Party Transaction [Line Items]
Costs incurred by related party	58.4	55.7	42.0
Prepaid balance to related party	5.9	4.5
Ipalco Enterprises, Inc. [Member]
Related Party Transaction [Line Items]
Costs incurred by related party	10.4	10.6	9.7
Indianapolis Power And Light Company
Related Party Transaction [Line Items]
Self-insured retention per occurrence	5.0
Insurance expense	7.0	5.6	4.3
Prepaid insurance			2.3	$ 2.3
Health coverage expense	23.7	21.0	20.2
Income taxes receivable	6.7	12.5
Deferred Compensation Arrangement with Individual, Compensation Expense	0.2	0.3	0.3
Costs incurred by related party	10.4	10.6	9.7
Prepaid balance to related party	5.9	4.5
Billings from related party	4.3	6.5	3.0
Loans to Parent, net of repayments	6.1
Contract with Customer, Liability	0.0	0.5
Loans to Parent, net of repayments	6.1
Indianapolis Power And Light Company | Service Company [Member]
Related Party Transaction [Line Items]
Costs incurred by related party	$ 58.2	$ 55.5	$ 41.8