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Benefit Plans (Amounts Recognized On The Consolidated Balance Sheets) (Details) - USD ($) $ in Millions | Dec. 31, 2023 | Dec. 31, 2022
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Amounts recognized on the balance sheets consist of: |  |
Pension and other benefit obligations | $ (249) | $ (277)
Pension Plans, Defined Benefit [Member] |  |
Amounts recognized on the balance sheets consist of: |  |
Non-current assets | 0 | 0
Current liabilities | (2) | (2)
Pension and other benefit obligations | (142) | (167)
Net amounts recognized at December 31 | (144) | (169)
Amounts recognized in Regulatory Assets consist of: |  |
Net actuarial loss | 337 | 376
Prior service credit | (2) | (3)
Net amount recognized at December 31 | 335 | 373
Other Postretirement Benefits Plans [Member] |  |
Amounts recognized on the balance sheets consist of: |  |
Non-current assets | 14 | 9
Current liabilities | (8) | (8)
Pension and other benefit obligations | (83) | (86)
Net amounts recognized at December 31 | (77) | (85)
Amounts recognized in Regulatory Assets consist of: |  |
Net actuarial loss | 11 | 20
Prior service credit | 0 | 0
Net amount recognized at December 31 | 11 | 20
IPL [Member] |  |
Amounts recognized on the balance sheets consist of: |  |
Pension and other benefit obligations | (51) | (62)
IPL [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 | (35) | (45)
Net amounts recognized at December 31 | (35) | (45)
Amounts recognized in Regulatory Assets consist of: |  |
Net actuarial loss | 135 | 154
Prior service credit | (1) | (1)
Net amount recognized at December 31 | 134 | 153
IPL [Member] | Other Postretirement Benefits Plans [Member] |  |
Amounts recognized on the balance sheets consist of: |  |
Non-current assets | 10 | 6
Current liabilities | (1) | (2)
Pension and other benefit obligations | (13) | (14)
Net amounts recognized at December 31 | (4) | (10)
Amounts recognized in Regulatory Assets consist of: |  |
Net actuarial loss | 9 | 14
Prior service credit | 0 | 0
Net amount recognized at December 31 | 9 | 14
WPL [Member] |  |
Amounts recognized on the balance sheets consist of: |  |
Pension and other benefit obligations | (121) | (140)
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 | (75) | (90)
Net amounts recognized at December 31 | (75) | (90)
Amounts recognized in Regulatory Assets consist of: |  |
Net actuarial loss | 148 | 165
Prior service credit | 0 | 0
Net amount recognized at December 31 | 148 | 165
WPL [Member] | Other Postretirement Benefits Plans [Member] |  |
Amounts recognized on the balance sheets consist of: |  |
Non-current assets | 4 | 3
Current liabilities | (6) | (5)
Pension and other benefit obligations | (45) | (49)
Net amounts recognized at December 31 | (47) | (51)
Amounts recognized in Regulatory Assets consist of: |  |
Net actuarial loss | 3 | 6
Prior service credit | 0 | 0
Net amount recognized at December 31 | $ 3 | $ 6

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