Plant, Property, and Equipment (Narrative) (Details) $ in Millions	1 Months Ended		12 Months Ended
	Aug. 31, 2023 USD ($)	May 31, 2023 USD ($) MW	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Covert Plant Acquisition
Property, Plant and Equipment [Line Items]
Consideration transferred	$ 2	$ 810	$ 812	$ 0	$ 0
Consumers Energy Company
Property, Plant and Equipment [Line Items]
Consideration transferred					2,052
Plant additions			3,100	2,300
Finance lease accumulated amortization			64	88
Consumers Energy Company | Covert Plant Acquisition
Property, Plant and Equipment [Line Items]
Consideration transferred			$ 812	$ 0	$ 0
New Covert Generating Facility | Consumers Energy Company
Property, Plant and Equipment [Line Items]
Nameplate capacity (in MW) | MW		1,200
Net book value of plant		$ 440
Plant acquisition adjustment		370
Plant additions		810
New Covert Generating Facility | Seller
Property, Plant and Equipment [Line Items]
Original cost of plant		665
Accumulated depreciation		$ 225