v3.25.4

Regulatory Matters (Narrative) (Details) $ in Millions | 1 Months Ended | 4 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jan. 31, 2026 USD ($) | Sep. 30, 2025 USD ($) | Jul. 31, 2025 USD ($) | Mar. 31, 2025 USD ($) | Dec. 31, 2024 USD ($) | Oct. 31, 2024 USD ($) | Jul. 31, 2024 USD ($) | May 31, 2024 USD ($) | Apr. 30, 2024 USD ($) | Dec. 31, 2025 USD ($) facility | Dec. 31, 2025 USD ($) facility | Dec. 31, 2024 USD ($) | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Dec. 31, 2016 unit | Dec. 31, 2015 unit | Dec. 31, 2013 USD ($)
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory assets |  |  |  |  | $ 3,569.0 |  |  |  |  | $ 3,355.0 | $ 3,355.0 | $ 3,569.0 |  |  |  |  |
Operating Revenue |  |  |  |  |  |  |  |  |  |  | 8,539.0 | 7,515.0 | $ 7,462.0 |  |  |  |
ASP gain |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gain on disposition of assets |  |  |  |  |  |  |  |  | $ 110.0 |  |  |  |  |  |  |  |
Amount credited to customers |  |  |  |  |  |  | $ 82.5 |  |  |  |  |  |  |  |  |  |
Ludington Overhaul Contract Dispute |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash expenditures |  |  |  |  |  |  |  |  |  |  | 30.0 |  |  |  |  |  |
Consumers Energy Company |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory assets |  |  |  |  | 3,569.0 |  |  |  |  | $ 3,355.0 | 3,355.0 | 3,569.0 |  |  |  |  |
Operating Revenue |  |  |  |  |  |  |  |  |  |  | $ 8,132.0 | 7,200.0 | $ 7,166.0 |  |  |  |
Consumers Energy Company | Renewable energy grant |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from government grant |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 69.0
Consumers Energy Company | MGP sites |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of former MGPs | facility |  |  |  |  |  |  |  |  |  | 23 | 23 |  |  |  |  |  |
Regulatory asset collection period |  |  |  |  |  |  |  |  |  | 10 years | 10 years |  |  |  |  |  |
Consumers Energy Company | Gas-Fueled Electric Generation |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of units retired | unit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3 |
Consumers Energy Company | Coal-Fueled Electric Generation |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of units retired | unit |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7 |  |
Consumers Energy Company | Energy Waste Reduction Plan Incentive |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory assets |  |  |  |  | 64.0 |  |  |  |  | $ 64.0 | $ 64.0 | 64.0 |  |  |  |  |
Consumers Energy Company | J.H. Campbell Generating Units |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory assets |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,300.0 |  |  |
Operating Revenue |  |  |  |  |  |  |  |  |  | 77.0 |  |  |  |  |  |  |
Rate of return on equity authorized |  |  |  |  |  |  |  |  |  |  |  |  |  | 9.00% |  |  |
Financial impact of emergency order |  |  |  |  |  |  |  |  |  | 93.0 |  |  |  |  |  |  |
Consumers Energy Company | J.H. Campbell Generating Units | Subsequent Event |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating Revenue | $ 78.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Financial impact of emergency order | 42.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Energy Waste Reduction Plan Incentive | Consumers Energy Company |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating Revenue |  |  |  |  |  |  |  |  |  |  | 64.0 |  |  |  |  |  |
Energy Waste Reduction Plan Incentive | Consumers Energy Company | Subsequent Event |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Authorized recovery collection | $ 64.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
PSCR underrecoveries | Consumers Energy Company |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
PSCR underrecoveries |  |  |  |  | 0.0 |  |  |  |  | $ 38.0 | $ 38.0 | $ 0.0 |  | $ 401.0 |  |  |
Gas Rate Case | Consumers Energy Company |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Requested annual rate increase |  |  |  |  | $ 248.0 |  |  |  |  |  |  |  |  |  |  |  |
Requested annual rate increase, as a percent |  |  |  |  | 10.25% |  |  |  |  |  |  |  |  |  |  |  |
Amended requested annual rate increase |  |  | $ 217.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gas Rate Case | Consumers Energy Company | ASP gain |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gain on sale utilized as offset |  |  |  |  |  |  | $ 27.5 |  |  |  |  |  |  |  |  |  |
Electric Rate Case |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amended requested annual rate increase |  |  |  |  |  | $ 277.0 |  |  |  |  |  |  |  |  |  |  |
Electric Rate Case | Consumers Energy Company |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rate of return on equity authorized |  | 9.80% |  | 9.90% |  |  |  |  |  |  |  |  |  |  |  |  |
Requested annual rate increase |  |  |  |  |  |  |  | $ 325.0 |  |  |  |  |  |  |  |  |
Requested annual rate increase, as a percent |  |  |  |  |  |  |  | 10.25% |  |  |  |  |  |  |  |  |
Surcharge for the recovery of excess distribution investments |  |  |  | $ 22.0 |  |  |  |  |  |  |  |  |  |  |  |  |
Additional annual rate increase authorized |  | $ 157.5 |  | $ 176.0 |  |  |  |  |  |  |  |  |  |  |  |  |
Electric Rate Case, First Component | Consumers Energy Company |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Requested annual rate increase |  |  |  |  |  |  |  | $ 303.0 |  |  |  |  |  |  |  |  |
Electric Rate Case, Second Component | Consumers Energy Company |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Surcharge for the recovery of excess distribution investments |  |  |  |  |  |  |  | $ 22.0 |  |  |  |  |  |  |  |  |

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