Plant, Property, and Equipment (Summary of Accumulated Depreciation and Amortization) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Public Utility, Property, Plant and Equipment [Line Items]
Accumulated depreciation and amortization	$ 9,569	$ 9,007
Consumers Energy Company
Public Utility, Property, Plant and Equipment [Line Items]
Consumers accumulated depreciation and amortization	9,310	8,796
Non-utility plant assets
Public Utility, Property, Plant and Equipment [Line Items]
Accumulated depreciation and amortization	262	217
Non-utility plant assets | Consumers Energy Company
Public Utility, Property, Plant and Equipment [Line Items]
Consumers accumulated depreciation and amortization	3	6
Utility plant assets
Public Utility, Property, Plant and Equipment [Line Items]
Accumulated depreciation and amortization	9,307	8,790
Utility plant assets | Consumers Energy Company
Public Utility, Property, Plant and Equipment [Line Items]
Consumers accumulated depreciation and amortization	$ 9,307	$ 8,790