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Benefit Plans (Expected Benefit Payments) (Details) $ in Millions | Dec. 31, 2022 USD ($)
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Defined Benefit Plan Disclosure [Line Items] |
Expected benefit payments, 2023 | $ 90
Expected benefit payments, 2024 | 89
Expected benefit payments, 2025 | 90
Expected benefit payments, 2026 | 91
Expected benefit payments, 2027 | 90
Expected benefit payments, 2028 - 2032 | 418
Defined Benefit Pension Plans [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Expected benefit payments, 2023 | 72
Expected benefit payments, 2024 | 71
Expected benefit payments, 2025 | 72
Expected benefit payments, 2026 | 74
Expected benefit payments, 2027 | 74
Expected benefit payments, 2028 - 2032 | 349
Other Postretirement Benefits Plans [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Expected benefit payments, 2023 | 18
Expected benefit payments, 2024 | 18
Expected benefit payments, 2025 | 18
Expected benefit payments, 2026 | 17
Expected benefit payments, 2027 | 16
Expected benefit payments, 2028 - 2032 | 69
IPL [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Expected benefit payments, 2023 | 41
Expected benefit payments, 2024 | 40
Expected benefit payments, 2025 | 41
Expected benefit payments, 2026 | 40
Expected benefit payments, 2027 | 39
Expected benefit payments, 2028 - 2032 | 182
IPL [Member] | Defined Benefit Pension Plans [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Expected benefit payments, 2023 | 34
Expected benefit payments, 2024 | 33
Expected benefit payments, 2025 | 34
Expected benefit payments, 2026 | 33
Expected benefit payments, 2027 | 32
Expected benefit payments, 2028 - 2032 | 155
IPL [Member] | Other Postretirement Benefits Plans [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Expected benefit payments, 2023 | 7
Expected benefit payments, 2024 | 7
Expected benefit payments, 2025 | 7
Expected benefit payments, 2026 | 7
Expected benefit payments, 2027 | 7
Expected benefit payments, 2028 - 2032 | 27
WPL [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Expected benefit payments, 2023 | 39
Expected benefit payments, 2024 | 38
Expected benefit payments, 2025 | 38
Expected benefit payments, 2026 | 38
Expected benefit payments, 2027 | 37
Expected benefit payments, 2028 - 2032 | 174
WPL [Member] | Defined Benefit Pension Plans [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Expected benefit payments, 2023 | 32
Expected benefit payments, 2024 | 31
Expected benefit payments, 2025 | 31
Expected benefit payments, 2026 | 31
Expected benefit payments, 2027 | 31
Expected benefit payments, 2028 - 2032 | 148
WPL [Member] | Other Postretirement Benefits Plans [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Expected benefit payments, 2023 | 7
Expected benefit payments, 2024 | 7
Expected benefit payments, 2025 | 7
Expected benefit payments, 2026 | 7
Expected benefit payments, 2027 | 6
Expected benefit payments, 2028 - 2032 | $ 26

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