Benefit Plans (Schedule Of Fair Value Of Pension Plan Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 820,684	$ 850,020	$ 769,704
Percentage by asset category	100.00%	100.00%
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 7,229	$ 6,769
Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	813,592	843,251
Short-Term Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 2,353	$ 2,221
Percentage by asset category	0.00%	0.00%
Short-Term Investments [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 2,490	$ 2,221
US Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 154,051	$ 118,255
Percentage by asset category	19.00%	14.00%
US Government Debt Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 324	$ 131
US Government Debt Securities [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	153,727	118,124
Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 183,203
Percentage by asset category	22.00%
Equity Funds [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 2,778
Equity Funds [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	180,425
Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 481,077
Percentage by asset category	59.00%
Fixed Income [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 1,637
Fixed Income [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	479,440
Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		$ 323,253
Percentage by asset category		38.00%
Domestic Equity Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		$ 2,839
Domestic Equity Securities [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		320,414
Foreign Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		$ 406,291
Percentage by asset category		48.00%
Foreign Equity Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		$ 1,578
Foreign Equity Securities [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		404,713
Indianapolis Power And Light Company
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 820,684	$ 850,020	$ 769,704
Percentage by asset category	100.00%	100.00%
Indianapolis Power And Light Company | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 7,229	$ 6,769
Indianapolis Power And Light Company | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	813,592	843,251
Indianapolis Power And Light Company | Short-Term Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 2,353	$ 2,221
Percentage by asset category	0.00%	0.00%
Indianapolis Power And Light Company | Short-Term Investments [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 2,490	$ 2,221
Indianapolis Power And Light Company | US Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 154,051	$ 118,255
Percentage by asset category	19.00%	14.00%
Indianapolis Power And Light Company | US Government Debt Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 324	$ 131
Indianapolis Power And Light Company | US Government Debt Securities [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	153,727	118,124
Indianapolis Power And Light Company | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 183,203
Percentage by asset category	22.00%
Indianapolis Power And Light Company | Equity Funds [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 2,778
Indianapolis Power And Light Company | Equity Funds [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	180,425
Indianapolis Power And Light Company | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 481,077
Percentage by asset category	59.00%
Indianapolis Power And Light Company | Fixed Income [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 1,637
Indianapolis Power And Light Company | Fixed Income [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 479,440
Indianapolis Power And Light Company | Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		$ 323,253
Percentage by asset category		38.00%
Indianapolis Power And Light Company | Domestic Equity Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		$ 2,839
Indianapolis Power And Light Company | Domestic Equity Securities [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		320,414
Indianapolis Power And Light Company | Foreign Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		$ 406,291
Percentage by asset category		48.00%
Indianapolis Power And Light Company | Foreign Equity Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		$ 1,578
Indianapolis Power And Light Company | Foreign Equity Securities [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		$ 404,713