Contingencies and Commitments (Contingencies And Commitments) (Details) $ in Millions	1 Months Ended			3 Months Ended		6 Months Ended		24 Months Ended
	Jul. 31, 2022 USD ($)	Jun. 30, 2022 USD ($) site	Sep. 30, 2020 USD ($)	Jun. 30, 2022 USD ($) site	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) site	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Loss Contingencies [Line Items]
Regulatory assets		$ 3,367		$ 3,367		$ 3,367		$ 2,259
Operating Revenue				1,920	$ 1,558	4,294	$ 3,571
Consumers Energy Company
Loss Contingencies [Line Items]
Regulatory assets		$ 3,367		3,367		3,367		2,259
Cost of gas sold				213	94	678	372
Operating Revenue				$ 1,802	$ 1,493	$ 4,085	$ 3,430
Consumers Energy Company | Ludington
Loss Contingencies [Line Items]
Ownership share		51.00%		51.00%		51.00%
Consumers Energy Company | Ludington Plant Overhaul Contract Dispute
Loss Contingencies [Line Items]
Damages sought		$ 15
Consumers Energy Company | J.H. Campbell 3 Plant Retirement Contract Dispute | Subsequent Event
Loss Contingencies [Line Items]
Damages sought	$ 37
Consumers Energy Company | Tax And Other Indemnity Obligations
Loss Contingencies [Line Items]
Carrying value of indemnity obligations		1		$ 1		$ 1
Consumers Energy Company | Manufactured Gas Plant
Loss Contingencies [Line Items]
Regulatory assets		107		107		107
Bay Harbor
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies		$ 44		$ 44		$ 44
Discounted projected costs rate		4.34%		4.34%		4.34%
Accrual for environmental loss contingencies, inflation rate		1.00%		1.00%		1.00%
Remaining undiscounted obligation amount		$ 55		$ 55		$ 55
CERCLA Liability | Consumers Energy Company
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies		3		3		3
CERCLA Liability | Minimum | Consumers Energy Company
Loss Contingencies [Line Items]
Remediation and other response activity costs		3		3		3
CERCLA Liability | Maximum | Consumers Energy Company
Loss Contingencies [Line Items]
Remediation and other response activity costs		8		8		8
Manufactured Gas Plant | Consumers Energy Company
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies		$ 57		$ 57		$ 57
Discounted projected costs rate		2.57%		2.57%		2.57%
Accrual for environmental loss contingencies, inflation rate		2.50%		2.50%		2.50%
Remaining undiscounted obligation amount		$ 60		$ 60		$ 60
Number of former MGPs | site		23		23		23
Regulatory asset collection period						10 years
Electric Utility | NREPA | Consumers Energy Company
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies		$ 2		$ 2		$ 2
Electric Utility | NREPA | Minimum | Consumers Energy Company
Loss Contingencies [Line Items]
Remediation and other response activity costs		2		2		2
Electric Utility | NREPA | Maximum | Consumers Energy Company
Loss Contingencies [Line Items]
Remediation and other response activity costs		4		4		4
Gas Utility | NREPA | Consumers Energy Company
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies		1		1		1
Gas Utility | NREPA | Maximum | Consumers Energy Company
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies		$ 3		3		3
Ray Compressor Station | Consumers Energy Company
Loss Contingencies [Line Items]
Plant additions								$ 17
Insurance recoveries received						13
Impairment charge				$ 10		$ 10
Ray Compressor Station | Consumers Energy Company | GCR underrecoveries
Loss Contingencies [Line Items]
Cost of gas sold			$ 7