Plant, Property, and Equipment (Schedule Of Plant, Property, and Equipment) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Public Utility, Property, Plant and Equipment [Line Items]
Plant, property, and equipment, gross	$ 29,893	$ 27,870	$ 25,368
Construction work in progress	961	1,085
Accumulated depreciation and amortization	(8,502)	(7,938)
Total plant, property, and equipment	22,352	21,017
Consumers Energy Company
Public Utility, Property, Plant and Equipment [Line Items]
Plant, property, and equipment, gross	28,771	26,757	24,963
Assets under finance leases and other financing	332	336	$ 340
Construction work in progress	915	1,058
Accumulated depreciation and amortization	(8,371)	(7,844)
Total plant, property, and equipment	21,315	19,971
Plant additions	2,400	2,000
Plant retirements	$ 361	220
Consumers Energy Company | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, consumers	3 years
Consumers Energy Company | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, consumers	125 years
Generation | Consumers Energy Company
Public Utility, Property, Plant and Equipment [Line Items]
Generation	$ 6,704	6,376
Generation | Consumers Energy Company | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, generation	22 years
Generation | Consumers Energy Company | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, generation	125 years
Distribution | Consumers Energy Company
Public Utility, Property, Plant and Equipment [Line Items]
Distribution	$ 9,815	9,130
Distribution | Consumers Energy Company | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, distribution	20 years
Distribution | Consumers Energy Company | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, distribution	75 years
Other | Consumers Energy Company
Public Utility, Property, Plant and Equipment [Line Items]
Other	$ 1,309	1,326
Other | Consumers Energy Company | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, other	5 years
Other | Consumers Energy Company | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, other	50 years
Assets under finance leases and other financing | Consumers Energy Company
Public Utility, Property, Plant and Equipment [Line Items]
Assets under finance leases and other financing	$ 319	323
Distribution | Consumers Energy Company
Public Utility, Property, Plant and Equipment [Line Items]
Distribution	$ 6,338	5,702
Distribution | Consumers Energy Company | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, distribution	20 years
Distribution | Consumers Energy Company | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, distribution	85 years
Transmission | Consumers Energy Company
Public Utility, Property, Plant and Equipment [Line Items]
Transmission	$ 2,319	2,003
Transmission | Consumers Energy Company | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, transmission	17 years
Transmission | Consumers Energy Company | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, transmission	75 years
Underground Storage Facilities | Consumers Energy Company
Public Utility, Property, Plant and Equipment [Line Items]
Other	$ 1,117	1,046
Underground Storage Facilities | Consumers Energy Company | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, other	27 years
Underground Storage Facilities | Consumers Energy Company | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, other	75 years
Other | Consumers Energy Company
Public Utility, Property, Plant and Equipment [Line Items]
Other	$ 814	817
Other | Consumers Energy Company | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, other	5 years
Other | Consumers Energy Company | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, other	50 years
Finance leases | Consumers Energy Company
Public Utility, Property, Plant and Equipment [Line Items]
Assets under finance leases and other financing	$ 13	13
Other non-utility property | Consumers Energy Company
Public Utility, Property, Plant and Equipment [Line Items]
Other non-utility property	$ 23	21
Other non-utility property | Consumers Energy Company | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, other	3 years
Other non-utility property | Consumers Energy Company | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, other	51 years
Natural Gas | Underground Storage Facilities | Consumers Energy Company
Public Utility, Property, Plant and Equipment [Line Items]
Other	$ 26	26
Enterprises independent power production
Public Utility, Property, Plant and Equipment [Line Items]
Plant, property, and equipment, gross	$ 1,121	1,112
Enterprises independent power production | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, Enterprises	2 years
Enterprises independent power production | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, Enterprises	40 years
Enterprises Other
Public Utility, Property, Plant and Equipment [Line Items]
Plant, property, and equipment, gross	$ 1	$ 1
Enterprises Other | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, Enterprises	3 years
Enterprises Other | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated depreciable life in years, Enterprises	5 years