Plant, Property, and Equipment (Schedule Of Depreciation And Amortization Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Depreciation expense – plant, property, and equipment	$ 975	$ 901	$ 841
Total depreciation and amortization expense	1,114	1,043	989
Securitized regulatory assets
Property, Plant and Equipment [Line Items]
Amortization expense	27	26	26
Software
Property, Plant and Equipment [Line Items]
Amortization expense	108	112	119
Other intangible assets
Property, Plant and Equipment [Line Items]
Amortization expense	4	4	3
Consumers Energy Company
Property, Plant and Equipment [Line Items]
Depreciation expense – plant, property, and equipment	938	881	827
Total depreciation and amortization expense	1,077	1,023	975
Consumers Energy Company | Securitized regulatory assets
Property, Plant and Equipment [Line Items]
Amortization expense	27	26	26
Consumers Energy Company | Software
Property, Plant and Equipment [Line Items]
Amortization expense	108	112	119
Consumers Energy Company | Other intangible assets
Property, Plant and Equipment [Line Items]
Amortization expense	$ 4	$ 4	$ 3