v3.25.4

Plant, Property, and Equipment (Summary of Finite-Lived Intangible Assets by Major Class) (Details) - Consumers Energy Company - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2025 | Dec. 31, 2024
Public Utility, Property, Plant and Equipment [Line Items] |  |
Gross cost | $ 987 | $ 989
Accumulated Amortization | 602 | 583
Plant additions | 3,100 | 2,100
Plant retirements | 387 | 390
Software development |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |
Gross cost | 649 | 679
Accumulated Amortization | 492 | 481
Rights of way |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |
Gross cost | 274 | 253
Accumulated Amortization | 72 | 68
Franchises and consents |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |
Gross cost | 16 | 16
Accumulated Amortization | 12 | 11
Leasehold improvements |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |
Gross cost | 15 | 13
Accumulated Amortization | 9 | 7
Other intangible assets |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |
Gross cost | 33 | 28
Accumulated Amortization | 17 | 16
Intangible plant |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |
Plant additions | 62 | 90
Plant retirements | $ 64 | $ 153
Minimum | Software development |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |
Amortization Life in Years | 3 years |
Minimum | Rights of way |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |
Amortization Life in Years | 50 years |
Minimum | Franchises and consents |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |
Amortization Life in Years | 5 years |
Maximum | Software development |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |
Amortization Life in Years | 15 years |
Maximum | Rights of way |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |
Amortization Life in Years | 85 years |
Maximum | Franchises and consents |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |
Amortization Life in Years | 50 years |

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