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Retirement Benefits (Schedule Of Expected Benefit Payments) (Details) $ in Millions | Dec. 31, 2018 USD ($)
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DB Pension Plans |
Defined Benefit Plan Disclosure [Line Items] |
2019 | $ 159
2020 | 162
2021 | 164
2022 | 165
2023 | 165
2024-2028 | 823
DB Pension Plans | Consumers Energy Company |
Defined Benefit Plan Disclosure [Line Items] |
2019 | 149
2020 | 152
2021 | 154
2022 | 155
2023 | 155
2024-2028 | 777
DB SERP |
Defined Benefit Plan Disclosure [Line Items] |
2019 | 10
2020 | 10
2021 | 10
2022 | 10
2023 | 10
2024-2028 | 46
DB SERP | Consumers Energy Company |
Defined Benefit Plan Disclosure [Line Items] |
2019 | 7
2020 | 7
2021 | 7
2022 | 7
2023 | 7
2024-2028 | 31
OPEB Plan |
Defined Benefit Plan Disclosure [Line Items] |
2019 | 59
2020 | 61
2021 | 64
2022 | 65
2023 | 66
2024-2028 | 328
OPEB Plan | Consumers Energy Company |
Defined Benefit Plan Disclosure [Line Items] |
2019 | 57
2020 | 59
2021 | 61
2022 | 62
2023 | 63
2024-2028 | $ 315

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