Stock-Based Compensation (Schedule Of Restricted Stock Activity - Granted) (Details)	12 Months Ended
	Dec. 31, 2021 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	561,068
Consumers Energy Company
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	530,234
Time-lapse awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	118,290
Time-lapse awards | Consumers Energy Company
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	112,128
Market-based awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	143,843
Market-based awards | Consumers Energy Company
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	135,638
Performance-based awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	143,843
Performance-based awards | Consumers Energy Company
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	135,638
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	11,725
Restricted stock units | Consumers Energy Company
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	11,035
Dividends on market-based awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	15,661
Dividends on market-based awards | Consumers Energy Company
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	14,890
Dividends on performance-based awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	15,964
Dividends on performance-based awards | Consumers Energy Company
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	15,175
Dividends on restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	2,142
Dividends on restricted stock units | Consumers Energy Company
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	2,058
Additional market-based shares based on achievement of condition
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	59,736
Additional market-based shares based on achievement of condition | Consumers Energy Company
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	56,505
Additional performance-based shares based on achievement of condition
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	49,864
Additional performance-based shares based on achievement of condition | Consumers Energy Company
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	47,167