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Benefit Plans (Amounts Recognized On The Consolidated Balance Sheets) (Details) - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
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Amounts recognized on the balance sheets consist of: |  |
Pension and other benefit obligations | $ (224) | $ (249)
Pension Plans, Defined Benefit [Member] |  |
Amounts recognized on the balance sheets consist of: |  |
Non-current assets | 0 | 0
Current liabilities | (3) | (2)
Pension and other benefit obligations | (123) | (142)
Net amounts recognized at December 31 | (126) | (144)
Amounts recognized in Regulatory Assets consist of: |  |
Net actuarial loss | 312 | 337
Prior service credit | (2) | (2)
Net amount recognized at December 31 | 310 | 335
Other Postretirement Benefits Plans [Member] |  |
Amounts recognized on the balance sheets consist of: |  |
Non-current assets | 17 | 14
Current liabilities | (7) | (8)
Pension and other benefit obligations | (78) | (83)
Net amounts recognized at December 31 | (68) | (77)
Amounts recognized in Regulatory Assets consist of: |  |
Net actuarial loss | 4 | 11
Prior service credit | 0 | 0
Net amount recognized at December 31 | 4 | 11
IPL [Member] |  |
Amounts recognized on the balance sheets consist of: |  |
Pension and other benefit obligations | (46) | (51)
IPL [Member] | Pension Plans, Defined Benefit [Member] |  |
Amounts recognized on the balance sheets consist of: |  |
Non-current assets | 0 | 0
Current liabilities | (1) | 0
Pension and other benefit obligations | (31) | (35)
Net amounts recognized at December 31 | (32) | (35)
Amounts recognized in Regulatory Assets consist of: |  |
Net actuarial loss | 126 | 135
Prior service credit | (1) | (1)
Net amount recognized at December 31 | 125 | 134
IPL [Member] | Other Postretirement Benefits Plans [Member] |  |
Amounts recognized on the balance sheets consist of: |  |
Non-current assets | 13 | 10
Current liabilities | (1) | (1)
Pension and other benefit obligations | (12) | (13)
Net amounts recognized at December 31 | 0 | (4)
Amounts recognized in Regulatory Assets consist of: |  |
Net actuarial loss | 7 | 9
Prior service credit | 0 | 0
Net amount recognized at December 31 | 7 | 9
WPL [Member] |  |
Amounts recognized on the balance sheets consist of: |  |
Pension and other benefit obligations | (102) | (121)
WPL [Member] | Pension Plans, Defined Benefit [Member] |  |
Amounts recognized on the balance sheets consist of: |  |
Non-current assets | 0 | 0
Current liabilities | 0 | 0
Pension and other benefit obligations | (62) | (75)
Net amounts recognized at December 31 | (62) | (75)
Amounts recognized in Regulatory Assets consist of: |  |
Net actuarial loss | 135 | 148
WPL [Member] | Other Postretirement Benefits Plans [Member] |  |
Amounts recognized on the balance sheets consist of: |  |
Non-current assets | 4 | 4
Current liabilities | (6) | (6)
Pension and other benefit obligations | (41) | (45)
Net amounts recognized at December 31 | (43) | (47)
Amounts recognized in Regulatory Assets consist of: |  |
Net actuarial loss | $ 0 | $ 3

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