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Stock-Based Compensation (Schedule Of Restricted Stock Granted) (Details) | 12 Months Ended
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Dec. 31, 2018 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 654,840
Consumers Energy Company |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 619,683
Time-lapse awards |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 122,615
Time-lapse awards | Consumers Energy Company |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 117,029
Market-based awards |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 134,179
Market-based awards | Consumers Energy Company |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 126,558
Performance-based awards |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 134,179
Performance-based awards | Consumers Energy Company |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 126,558
Restricted stock units |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 11,196
Restricted stock units | Consumers Energy Company |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 10,792
Dividend equivalents on market-based awards |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 21,154
Dividend equivalents on market-based awards | Consumers Energy Company |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 20,077
Dividend equivalents on performance-based awards |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 25,925
Dividend equivalents on performance-based awards | Consumers Energy Company |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 24,583
Dividend equivalents on restricted stock units |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 1,254
Dividend equivalents on restricted stock units | Consumers Energy Company |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 1,142
Additional market-based shares based on achievement of condition |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 88,987
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) | 84,025
Additional performance-based shares based on achievement of condition |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted (in shares) | 115,351
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) | 108,919

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