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Financings and Capitalization Financings and Capitalization (Debt Retirements) (Details) $ in Millions | 9 Months Ended
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Sep. 30, 2020 USD ($)
Debt Instrument [Line Items] |
Redemption of debt | $ 725
Consumers Energy Company |
Debt Instrument [Line Items] |
Redemption of debt | 725
Consumers Energy Company | First Mortgage Bonds due October 2020 |
Debt Instrument [Line Items] |
Redemption of debt | $ 100
Interest Rate | 3.77%
Consumers Energy Company | First Mortgage Bonds Due September 2022 |
Debt Instrument [Line Items] |
Redemption of debt | $ 250
Interest Rate | 5.30%
Consumers Energy Company | First Mortgage Bonds Due May 2022 |
Debt Instrument [Line Items] |
Redemption of debt | $ 375
Interest Rate | 2.85%

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