Benefit Plans (Schedule Of Defined Benefit Plans Disclosures) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Change in benefit obligation:
Projected benefit obligation at beginning Measurement Date (see below)	$ 577,529
Service cost	5,189	$ 8,949	$ 9,339
Interest cost	29,818	18,099	15,660
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(9,681)	182,590
Amendments (primarily increases in pension bands)	653	0
Defined Benefit Plan, Benefit Obligation, Payment for Settlement	0	(394)
Benefits paid	73,325	38,575
Projected benefit obligation at ending Measurement Date	549,546	577,529
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	611,125	820,684
Actual return on plan assets	52,905	(171,002)
Employer contributions during quarter	114	412	0
Defined Benefit Plan, Plan Assets, Payment for Settlement	0	394
Benefits paid	(73,325)	(38,575)
Defined Benefit Plan Fair Value of plan assets	590,819	611,125
Fair value of plan assets at ending Measurement Date	590,819	611,125	820,684
Unfunded status	41,273	33,596
Asset, Defined Benefit Pension Plan, Noncurrent	(41,273)	(33,611)
Amounts recognized in the statement of financial position under ASC 715:
Noncurrent liabilities	0	(15)
Asset, Defined Benefit Plan, Noncurrent, Net	41,273	33,596
Sources of change in regulatory assets(1):
Prior service cost (credit) arising during period	653	0
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax	10,100
Net loss (gain) arising during period	(10,117)	(24,069)
Amortization of prior service cost	(2,172)	(2,589)
Amortization of gain (loss)	(6,145)	(2,622)
Total recognized in regulatory assets	(17,781)	18,858
Net loss (gain)	115,297	131,559
Prior service cost (credit)	10,136	11,655
Total amounts included in regulatory assets (liabilities)	$ 125,433	$ 143,214
Percentage by asset category	100.00%	100.00%
Assets for Plan Benefits, Defined Benefit Plan	$ 41,172	$ 33,611
Expected return on plan assets	5.60%
Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	$ 6,480
Fair value of plan assets at ending Measurement Date	6,404	6,480
Significant Observable Inputs (Level 2) [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	604,645
Fair value of plan assets at ending Measurement Date	584,415	604,645
Indianapolis Power And Light Company
Change in benefit obligation:
Projected benefit obligation at beginning Measurement Date (see below)	577,529
Service cost	5,189	8,949	9,339
Interest cost	29,818	18,099	15,660
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(9,681)	(182,590)
Amendments (primarily increases in pension bands)	653	0
Defined Benefit Plan, Benefit Obligation, Payment for Settlement	0	(394)
Benefits paid	(73,325)	38,575
Projected benefit obligation at ending Measurement Date	549,546	577,529
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	611,125	820,684
Actual return on plan assets	52,905	(171,002)
Employer contributions during quarter	114	412	0
Defined Benefit Plan, Plan Assets, Payment for Settlement	0	(394)
Benefits paid	(73,325)	(38,575)
Fair value of plan assets at ending Measurement Date	590,819	611,125	$ 820,684
Unfunded status	41,273	33,596
Asset, Defined Benefit Pension Plan, Noncurrent	(41,273)	(33,611)
Amounts recognized in the statement of financial position under ASC 715:
Noncurrent liabilities	0	(15)
Asset, Defined Benefit Plan, Noncurrent, Net	41,273	33,596
Sources of change in regulatory assets(1):
Prior service cost (credit) arising during period	653	0
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax	(10,117)
Net loss (gain) arising during period	10,100	(24,069)
Amortization of prior service cost	(2,172)	(2,589)
Amortization of gain (loss)	(6,145)	(2,622)
Total recognized in regulatory assets	(17,781)	18,858
Net loss (gain)	115,297	131,559
Prior service cost (credit)	10,136	11,655
Total amounts included in regulatory assets (liabilities)	$ 125,433	$ 143,214
Percentage by asset category	100.00%	100.00%
Assets for Plan Benefits, Defined Benefit Plan	$ 41,172	$ 33,611
Expected return on plan assets	5.60%	5.60%
Indianapolis Power And Light Company | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	$ 6,480
Fair value of plan assets at ending Measurement Date	6,404	$ 6,480
Indianapolis Power And Light Company | Significant Observable Inputs (Level 2) [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	604,645
Fair value of plan assets at ending Measurement Date	584,415	604,645
US Government Debt Securities [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	122,704
Fair value of plan assets at ending Measurement Date	$ 117,397	$ 122,704
Sources of change in regulatory assets(1):
Percentage by asset category	20.00%	20.00%
US Government Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	$ 420
Fair value of plan assets at ending Measurement Date	178	$ 420
US Government Debt Securities [Member] | Significant Observable Inputs (Level 2) [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	122,284
Fair value of plan assets at ending Measurement Date	117,219	122,284
US Government Debt Securities [Member] | Indianapolis Power And Light Company
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	122,704
Fair value of plan assets at ending Measurement Date	$ 117,397	$ 122,704
Sources of change in regulatory assets(1):
Percentage by asset category	20.00%	20.00%
US Government Debt Securities [Member] | Indianapolis Power And Light Company | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	$ 420
Fair value of plan assets at ending Measurement Date	178	$ 420
US Government Debt Securities [Member] | Indianapolis Power And Light Company | Significant Observable Inputs (Level 2) [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	122,284
Fair value of plan assets at ending Measurement Date	117,219	122,284
Defined Benefit Plan, Common Collective Trust
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	608,336
Fair value of plan assets at ending Measurement Date	$ 588,028	$ 608,336
Sources of change in regulatory assets(1):
Percentage by asset category	100.00%	100.00%
Defined Benefit Plan, Common Collective Trust | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	$ 3,691
Fair value of plan assets at ending Measurement Date	3,613	$ 3,691
Defined Benefit Plan, Common Collective Trust | Significant Observable Inputs (Level 2) [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	604,645
Fair value of plan assets at ending Measurement Date	584,415	604,645
Defined Benefit Plan, Common Collective Trust | Indianapolis Power And Light Company
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	608,336
Fair value of plan assets at ending Measurement Date	$ 588,028	$ 608,336
Sources of change in regulatory assets(1):
Percentage by asset category	100.00%	100.00%
Defined Benefit Plan, Common Collective Trust | Indianapolis Power And Light Company | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	$ 3,691
Fair value of plan assets at ending Measurement Date	3,613	$ 3,691
Defined Benefit Plan, Common Collective Trust | Indianapolis Power And Light Company | Significant Observable Inputs (Level 2) [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	604,645
Fair value of plan assets at ending Measurement Date	584,415	604,645
Short-Term Investments [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	2,789
Fair value of plan assets at ending Measurement Date	$ 2,791	$ 2,789
Sources of change in regulatory assets(1):
Percentage by asset category	0.00%	0.00%
Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	$ 2,789
Fair value of plan assets at ending Measurement Date	2,791	$ 2,789
Short-Term Investments [Member] | Significant Observable Inputs (Level 2) [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	0
Fair value of plan assets at ending Measurement Date	0	0
Short-Term Investments [Member] | Indianapolis Power And Light Company
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	2,789
Fair value of plan assets at ending Measurement Date	$ 2,791	$ 2,789
Sources of change in regulatory assets(1):
Percentage by asset category	0.00%	0.00%
Short-Term Investments [Member] | Indianapolis Power And Light Company | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	$ 2,789
Fair value of plan assets at ending Measurement Date	2,791	$ 2,789
Equity Securities | Indianapolis Power And Light Company
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	85,341
Fair value of plan assets at ending Measurement Date		$ 85,341
Sources of change in regulatory assets(1):
Percentage by asset category		14.00%
Equity Securities | Indianapolis Power And Light Company | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	2,017
Fair value of plan assets at ending Measurement Date		$ 2,017
Equity Securities | Indianapolis Power And Light Company | Significant Observable Inputs (Level 2) [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	83,324
Fair value of plan assets at ending Measurement Date		83,324
Fixed Income [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	400,291
Fair value of plan assets at ending Measurement Date	$ 387,979	$ 400,291
Sources of change in regulatory assets(1):
Percentage by asset category	66.00%	66.00%
Fixed Income [Member] | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	$ 1,254
Fair value of plan assets at ending Measurement Date	1,168	$ 1,254
Fixed Income [Member] | Significant Observable Inputs (Level 2) [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	399,037
Fair value of plan assets at ending Measurement Date	386,811	399,037
Fixed Income [Member] | Indianapolis Power And Light Company
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	400,291
Fair value of plan assets at ending Measurement Date	$ 387,979	$ 400,291
Sources of change in regulatory assets(1):
Percentage by asset category	66.00%	66.00%
Fixed Income [Member] | Indianapolis Power And Light Company | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	$ 1,254
Fair value of plan assets at ending Measurement Date	1,168	$ 1,254
Fixed Income [Member] | Indianapolis Power And Light Company | Significant Observable Inputs (Level 2) [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	399,037
Fair value of plan assets at ending Measurement Date	386,811	399,037
Equity Funds [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	85,341
Fair value of plan assets at ending Measurement Date	$ 82,652	$ 85,341
Sources of change in regulatory assets(1):
Percentage by asset category	14.00%	14.00%
Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	$ 2,017
Fair value of plan assets at ending Measurement Date	2,267	$ 2,017
Equity Funds [Member] | Significant Observable Inputs (Level 2) [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	83,324
Fair value of plan assets at ending Measurement Date	80,385	$ 83,324
Equity Funds [Member] | Indianapolis Power And Light Company
Change in plan assets:
Fair value of plan assets at beginning Measurement Date
Fair value of plan assets at ending Measurement Date	$ 82,652
Sources of change in regulatory assets(1):
Percentage by asset category	14.00%
Equity Funds [Member] | Indianapolis Power And Light Company | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date
Fair value of plan assets at ending Measurement Date	$ 2,267
Equity Funds [Member] | Indianapolis Power And Light Company | Significant Observable Inputs (Level 2) [Member]
Change in plan assets:
Fair value of plan assets at beginning Measurement Date
Fair value of plan assets at ending Measurement Date	$ 80,385