Regulatory Matters (Schedule Of Regulatory Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Public Utilities, General Disclosures [Line Items]
Total current regulatory assets	$ 57	$ 46
Total non-current regulatory assets	3,595	2,259
Total current regulatory liabilities	104	146
Total non-current regulatory liabilities	3,796	3,802
Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total current regulatory assets	57	46
Total non-current regulatory assets	3,595	2,259
Total regulatory assets	3,652	2,305
Total current regulatory liabilities	104	146
Total non-current regulatory liabilities	3,796	3,802
Total regulatory liabilities	3,900	3,948
Cost of removal | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory liabilities	2,426	2,375
Income taxes, net | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total current regulatory liabilities	48	138
Total non-current regulatory liabilities	1,267	1,297
Reserve for customer refunds | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total current regulatory liabilities	47	2	$ 28
Renewable energy grant | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory liabilities	45	47
Renewable energy plan | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory liabilities	32	13
Postretirement benefits | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory liabilities	0	54
Other | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total current regulatory liabilities	9	6
Total non-current regulatory liabilities	8	9
Costs of coal-fueled electric generating units to be retired | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	1,960	678
Postretirement benefits | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	856	837
ARO | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	281	247
Securitized costs | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	165	193
MGP Sites | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	108	112
Unamortized Loss On Reacquired Debt | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	100	104
Energy Waste Reduction Plan Incentive | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total current regulatory assets	47	42
Total non-current regulatory assets	55	46
Retention Incentive Program | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	31	7
Demand response program | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	12	10
Total non-current regulatory liabilities	12	7
Energy Waste Reduction Plan | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	10	13
Total non-current regulatory liabilities	6	0
Other | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total current regulatory assets	10	4
Total non-current regulatory assets	$ 17	$ 12