Regulatory Matters (Schedule Of The Components Of PSCR And GCR Over/(Under) Recoveries) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Public Utilities, General Disclosures [Line Items]
Accrued gas revenue	$ 0	$ 16
Accrued rate refunds	35	4
Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Accrued gas revenue	0	16
Accrued rate refunds	35	4
Consumers Energy Company | GCR overrecoveries/underrecoveries
Public Utilities, General Disclosures [Line Items]
Accrued gas revenue	0	16
Accrued rate refunds	2	0
Consumers Energy Company | PSCR overrecoveries
Public Utilities, General Disclosures [Line Items]
Accrued rate refunds	$ 33	$ 4