Plant, Property, and Equipment (Summary of Depreciation and Amortization Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Depreciation expense – plant, property, and equipment	$ 1,050	$ 990	$ 975
Total depreciation and amortization expense	1,180	1,126	1,114
Securitized regulatory assets
Property, Plant and Equipment [Line Items]
Amortization expense	33	28	27
Software
Property, Plant and Equipment [Line Items]
Amortization expense	92	103	108
Other intangible assets
Property, Plant and Equipment [Line Items]
Amortization expense	5	5	4
Consumers Energy Company
Property, Plant and Equipment [Line Items]
Depreciation expense – plant, property, and equipment	1,007	952	938
Total depreciation and amortization expense	1,137	1,088	1,077
Consumers Energy Company | Securitized regulatory assets
Property, Plant and Equipment [Line Items]
Amortization expense	33	28	27
Consumers Energy Company | Software
Property, Plant and Equipment [Line Items]
Amortization expense	92	103	108
Consumers Energy Company | Other intangible assets
Property, Plant and Equipment [Line Items]
Amortization expense	$ 5	$ 5	$ 4