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Leases And Palisades Financing (Narrative) (Details) $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2018 USD ($) MW | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($)
Consumers Energy Company |  |  |
Leases [Line Items] |  |  |
Finance lease term | 15 years |  |
Coal-Carrying Railcars | Consumers Energy Company |  |  |
Leases [Line Items] |  |  |
Operating leases without extension provisions, remaining term | 5 years |  |
Operating leases with extension provisions, remaining term | 8 years |  |
Gas Transportation Pipeline into Karn | Consumers Energy Company |  |  |
Leases [Line Items] |  |  |
Capital lease term | 15 years |  |
Capital lease remaining term | 3 years |  |
Gas Transportation Pipeline into Zeeland | Consumers Energy Company |  |  |
Leases [Line Items] |  |  |
Capital lease term | 5 years |  |
Minimum | Coal-Carrying Railcars | Consumers Energy Company |  |  |
Leases [Line Items] |  |  |
Operating leases, term | 7 years |  |
Minimum | Gas Transportation Pipeline into Zeeland | Consumers Energy Company |  |  |
Leases [Line Items] |  |  |
Capital lease renewal term | 5 years |  |
Minimum | Long-term PPAs | Consumers Energy Company |  |  |
Leases [Line Items] |  |  |
Lease term | 1 year |  |
Maximum | Coal-Carrying Railcars | Consumers Energy Company |  |  |
Leases [Line Items] |  |  |
Operating leases, term | 15 years |  |
Maximum | Vehicle Fleet Operations | Consumers Energy Company |  |  |
Leases [Line Items] |  |  |
Capital lease term | 120 months |  |
Maximum | Gas Transportation Pipeline into Zeeland | Consumers Energy Company |  |  |
Leases [Line Items] |  |  |
Capital lease renewal term | 10 years |  |
Maximum | Long-term PPAs | Consumers Energy Company |  |  |
Leases [Line Items] |  |  |
Lease term | 15 years |  |
Palisades Financing |  |  |
Leases [Line Items] |  |  |
Amortization and interest charges | $ 16 | $ 17 | $ 17
Asset and financing obligation | 42 |  |
Palisades Financing | Consumers Energy Company |  |  |
Leases [Line Items] |  |  |
Asset and financing obligation | $ 42 |  |
Palisades PPA | Consumers Energy Company |  |  |
Leases [Line Items] |  |  |
Annual average capacity (in MW) | MW | 798 |  |

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