Plant, Property, and Equipment (Summary of Depreciation and Amortization Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Depreciation expense – plant, property, and equipment	$ 1,041	$ 1,050	$ 990
Total depreciation and amortization expense	1,240	1,180	1,126
Other regulatory assets
Property, Plant and Equipment [Line Items]
Amortization expense	2	0	0
Securitized regulatory assets
Property, Plant and Equipment [Line Items]
Amortization expense	111	33	28
Software
Property, Plant and Equipment [Line Items]
Amortization expense	81	92	103
Other intangible assets
Property, Plant and Equipment [Line Items]
Amortization expense	5	5	5
Consumers Energy Company
Property, Plant and Equipment [Line Items]
Depreciation expense – plant, property, and equipment	992	1,007	952
Total depreciation and amortization expense	1,191	1,137	1,088
Consumers Energy Company | Other regulatory assets
Property, Plant and Equipment [Line Items]
Amortization expense	2	0	0
Consumers Energy Company | Securitized regulatory assets
Property, Plant and Equipment [Line Items]
Amortization expense	111	33	28
Consumers Energy Company | Software
Property, Plant and Equipment [Line Items]
Amortization expense	81	92	103
Consumers Energy Company | Other intangible assets
Property, Plant and Equipment [Line Items]
Amortization expense	$ 5	$ 5	$ 5