Benefit Plans (Schedule Of Net Periodic Benefit Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 5,189	$ 8,949	$ 9,339
Interest cost	29,818	18,099	15,660
Expected return on assets	(33,107)	(35,656)	(41,815)
Defined Benefit Plan Amortization of prior service cost net of acceleration component of curtailment charge	2,172	2,589	2,944
Amortization of actuarial loss	6,145	2,424	5,529
Amortization of settlement loss	0	199	0
Net periodic benefit cost	10,217	(3,396)	(8,343)
Less: amounts capitalized	(1,689)	(316)	(771)
Amount charged to expense	$ 8,528	(3,080)	(7,572)
Expected return on plan assets	5.60%
Asset, Defined Benefit Pension Plan, Noncurrent	$ 41,273	33,611
Indianapolis Power And Light Company
Defined Benefit Plan Disclosure [Line Items]
Service cost	5,189	8,949	9,339
Interest cost	29,818	18,099	15,660
Expected return on assets	(33,107)	(35,656)	(41,815)
Defined Benefit Plan Amortization of prior service cost net of acceleration component of curtailment charge	2,172	2,589	2,944
Amortization of actuarial loss	6,145	2,424	5,529
Amortization of settlement loss	0	199	0
Net periodic benefit cost	10,217	(3,396)	(8,343)
Less: amounts capitalized	1,689	(316)	(771)
Amount charged to expense	$ 8,528	$ (3,080)	$ (7,572)
Expected return on plan assets	5.60%	5.60%
Asset, Defined Benefit Pension Plan, Noncurrent	$ 41,273	$ 33,611
Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	5.41%	2.83%	2.46%
Expected return on plan assets	5.60%	4.45%	5.05%
Pension Benefit [Member] | Indianapolis Power And Light Company
Defined Benefit Plan Disclosure [Line Items]
Discount rate	5.41%	2.83%	2.46%
Expected return on plan assets	5.60%	4.45%	5.05%
Supplemental Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	5.32%	2.62%	2.31%
Expected return on plan assets	6.45%	5.50%	3.60%
Supplemental Retirement Plan [Member] | Indianapolis Power And Light Company
Defined Benefit Plan Disclosure [Line Items]
Discount rate	5.32%	2.62%	2.31%
Expected return on plan assets	6.45%	5.50%	3.60%