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Regulatory Matters (Schedule of Components of the Annual Rate Increase Requested) (Details) - 2016 Electric Rate Case [Member] - Consumers Energy Company [Member] $ in Millions | 1 Months Ended
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Mar. 31, 2016 USD ($)
Public Utilities, General Disclosures [Line Items] |
Annual rate increase requested | $ 225
Investment In Rate Base [Member] |
Public Utilities, General Disclosures [Line Items] |
Annual rate increase requested | 161
Operating And Maintenance Costs [Member] |
Public Utilities, General Disclosures [Line Items] |
Annual rate increase requested | 21
Gross Margin [Member] |
Public Utilities, General Disclosures [Line Items] |
Annual rate increase requested | 17
Cost Of Capital [Member] |
Public Utilities, General Disclosures [Line Items] |
Annual rate increase requested | 15
Working Capital [Member] |
Public Utilities, General Disclosures [Line Items] |
Annual rate increase requested | $ 11

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