Income Taxes (Loss And Credit Carryforwards) (Details) $ in Millions	Dec. 31, 2022 USD ($)
Operating Loss Carryforwards [Line Items]
General business credits	$ 320
Total tax attributes	385
Consumers Energy Company
Operating Loss Carryforwards [Line Items]
General business credits	99
Total tax attributes	145
State Tax Authority
Operating Loss Carryforwards [Line Items]
Local net operating loss carryforwards	60
State Tax Authority | Consumers Energy Company
Operating Loss Carryforwards [Line Items]
Local net operating loss carryforwards	46
Local Tax Authority
Operating Loss Carryforwards [Line Items]
Local net operating loss carryforwards	3
Federal Tax Authority
Operating Loss Carryforwards [Line Items]
Federal charitable contribution carryforwards	$ 2