Plant, Property, and Equipment (Summary of Depreciation and Amortization Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Depreciation expense – plant, property, and equipment	$ 1,099	$ 1,041	$ 1,050
Total depreciation and amortization expense	1,306	1,240	1,180
Other regulatory assets
Property, Plant and Equipment [Line Items]
Amortization expense	8	2	0
Securitized regulatory assets
Property, Plant and Equipment [Line Items]
Amortization expense	117	111	33
Software
Property, Plant and Equipment [Line Items]
Amortization expense	75	81	92
Other intangible assets
Property, Plant and Equipment [Line Items]
Amortization expense	7	5	5
Consumers Energy Company
Property, Plant and Equipment [Line Items]
Depreciation expense – plant, property, and equipment	1,047	992	1,007
Total depreciation and amortization expense	1,254	1,191	1,137
Consumers Energy Company | Other regulatory assets
Property, Plant and Equipment [Line Items]
Amortization expense	8	2	0
Consumers Energy Company | Securitized regulatory assets
Property, Plant and Equipment [Line Items]
Amortization expense	117	111	33
Consumers Energy Company | Software
Property, Plant and Equipment [Line Items]
Amortization expense	75	81	92
Consumers Energy Company | Other intangible assets
Property, Plant and Equipment [Line Items]
Amortization expense	$ 7	$ 5	$ 5