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v3.23.2

Transition Activities - Narrative (Details) $ in Millions | 1 Months Ended | 3 Months Ended | 6 Months Ended | 12 Months Ended | 45 Months Ended |
--- | --- | --- | --- | --- | --- | ---
May 31, 2023 USD ($) MW | Jun. 30, 2023 USD ($) coal_fueled_electric_generating_unit | Jun. 30, 2022 USD ($) | Jun. 30, 2023 USD ($) coal_fueled_electric_generating_unit | Jun. 30, 2022 USD ($) | Jun. 30, 2023 USD ($) coal_fueled_electric_generating_unit | Jun. 30, 2023 USD ($) coal_fueled_electric_generating_unit | Dec. 31, 2022 USD ($)
New Covert Generating Facility | Consumers Energy Company |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Nameplate capacity (in MW) | MW | 1,200 |  |  |  |  |  |  |
Consideration transferred | $ 810 |  |  |  |  |  |  |
Net book value of plant | 440 |  |  |  |  |  |  |
Plant acquisition adjustment | 370 |  |  |  |  |  |  |
Increase to property, plant, and equipment | 810 |  |  |  |  |  |  |
New Covert Generating Facility | Seller |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Original cost of plant | 665 |  |  |  |  |  |  |
Accumulated depreciation | $ 225 |  |  |  |  |  |  |
D.E. Karn Generating Complex | Consumers Energy Company | Costs of coal-fueled electric generating units to be retired |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Regulatory assets, number of units | coal_fueled_electric_generating_unit |  | 2 |  | 2 |  | 2 | 2 |
Regulatory asset |  | $ 670 |  | $ 670 |  | $ 670 | $ 670 |
Retention Benefits |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Cost deferred |  | $ 5 | $ 2 | $ 10 | $ 3 |  |  |
Retention Benefits | D.E. Karn Generating Complex and J.H. Campbell Generating Units | Retention Incentive Program |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Regulatory asset collection period |  | 3 years |  | 3 years |  | 3 years | 3 years |
Retention Benefits | D.E. Karn Generating Complex |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Aggregate cost incurred |  |  |  |  |  |  |  | $ 32
Retention and severance costs |  |  |  |  |  |  | $ 16 |
Retention Benefits | D.E. Karn Generating Complex | Retention Incentive Program |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Cost deferred |  |  |  |  |  |  | 12 |
Retention Benefits | D.E. Karn Generating Complex | Property, Plant and Equipment |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Costs incurred and capitalized |  |  |  |  |  |  | 4 |
Retention Benefits | J.H. Campbell Generating Units |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Expected cost |  | $ 50 |  | $ 50 |  | $ 50 | $ 50 |
Retention Benefits | J.H. Campbell Generating Units | Retention Incentive Program |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Cost deferred |  |  |  |  |  | $ 28 |  |

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