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v2.4.1.9

Plant, Property, and Equipment (Schedule of Finite-Lived Intangible Assets by Major Class Table) (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2014 | Dec. 31, 2013
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross | $ 1,004 us-gaap_FiniteLivedIntangibleAssetsGross | $ 909 us-gaap_FiniteLivedIntangibleAssetsGross | [1]
Finite-Lived Intangible Assets, Accumulated Amortization | 331 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization | 280 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization |
Public Utilities, Property Plant and Equipment Additions | 1,600 cms_PublicUtilitiesPropertyPlantAndEquipmentAdditions | 1,300 cms_PublicUtilitiesPropertyPlantAndEquipmentAdditions |
Consumers Energy Company [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross | 1,002 us-gaap_FiniteLivedIntangibleAssetsGross / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember | 906 us-gaap_FiniteLivedIntangibleAssetsGross / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember | [1]
Finite-Lived Intangible Assets, Accumulated Amortization | 329 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember | 279 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember |
Public Utilities, Property Plant and Equipment Additions | 1,600 cms_PublicUtilitiesPropertyPlantAndEquipmentAdditions / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember | 1,300 cms_PublicUtilitiesPropertyPlantAndEquipmentAdditions / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember |
Software and Software Development Costs [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross | 596 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_SoftwareAndSoftwareDevelopmentCostsMember | 508 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_SoftwareAndSoftwareDevelopmentCostsMember | [1]
Finite-Lived Intangible Assets, Accumulated Amortization | 223 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_SoftwareAndSoftwareDevelopmentCostsMember | 174 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_SoftwareAndSoftwareDevelopmentCostsMember |
Software and Software Development Costs [Member] | Consumers Energy Company [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross | 594 us-gaap_FiniteLivedIntangibleAssetsGross / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_SoftwareAndSoftwareDevelopmentCostsMember | 506 us-gaap_FiniteLivedIntangibleAssetsGross / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_SoftwareAndSoftwareDevelopmentCostsMember | [1]
Finite-Lived Intangible Assets, Accumulated Amortization | 221 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_SoftwareAndSoftwareDevelopmentCostsMember | 173 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_SoftwareAndSoftwareDevelopmentCostsMember |
Plant Acquisition Adjustments [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross | 217 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_PropertyPlantAndEquipmentByTypeAxis = cms_PlantAcquisitionAdjustmentsMember | 216 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_PropertyPlantAndEquipmentByTypeAxis = cms_PlantAcquisitionAdjustmentsMember | [1]
Finite-Lived Intangible Assets, Accumulated Amortization | 38 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_PropertyPlantAndEquipmentByTypeAxis = cms_PlantAcquisitionAdjustmentsMember | 32 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_PropertyPlantAndEquipmentByTypeAxis = cms_PlantAcquisitionAdjustmentsMember |
Plant Acquisition Adjustments [Member] | Consumers Energy Company [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross | 217 us-gaap_FiniteLivedIntangibleAssetsGross / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember / us-gaap_PropertyPlantAndEquipmentByTypeAxis = cms_PlantAcquisitionAdjustmentsMember | 216 us-gaap_FiniteLivedIntangibleAssetsGross / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember / us-gaap_PropertyPlantAndEquipmentByTypeAxis = cms_PlantAcquisitionAdjustmentsMember | [1]
Finite-Lived Intangible Assets, Accumulated Amortization | 38 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember / us-gaap_PropertyPlantAndEquipmentByTypeAxis = cms_PlantAcquisitionAdjustmentsMember | 32 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember / us-gaap_PropertyPlantAndEquipmentByTypeAxis = cms_PlantAcquisitionAdjustmentsMember |
Leasehold Improvements [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross | 5 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_LeaseholdImprovementsMember | 14 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_LeaseholdImprovementsMember | [1]
Finite-Lived Intangible Assets, Accumulated Amortization | 4 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_LeaseholdImprovementsMember | 11 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_LeaseholdImprovementsMember |
Leasehold Improvements [Member] | Consumers Energy Company [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross | 5 us-gaap_FiniteLivedIntangibleAssetsGross / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_LeaseholdImprovementsMember | 14 us-gaap_FiniteLivedIntangibleAssetsGross / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_LeaseholdImprovementsMember | [1]
Finite-Lived Intangible Assets, Accumulated Amortization | 4 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_LeaseholdImprovementsMember | 11 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_LeaseholdImprovementsMember |
Intangible Plant [Member] | Consumers Energy Company [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Public Utilities, Property Plant and Equipment Additions | 96 cms_PublicUtilitiesPropertyPlantAndEquipmentAdditions / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember / us-gaap_PropertyPlantAndEquipmentByTypeAxis = cms_IntangiblePlantMember | 53 cms_PublicUtilitiesPropertyPlantAndEquipmentAdditions / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember / us-gaap_PropertyPlantAndEquipmentByTypeAxis = cms_IntangiblePlantMember |
Rights of Way [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross | 150 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_ContractualRightsMember | 135 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_ContractualRightsMember | [1]
Finite-Lived Intangible Assets, Accumulated Amortization | 44 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_ContractualRightsMember | 42 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_ContractualRightsMember |
Rights of Way [Member] | Consumers Energy Company [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross | 150 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_ContractualRightsMember / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember | 135 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_ContractualRightsMember / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember | [1]
Finite-Lived Intangible Assets, Accumulated Amortization | 44 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_ContractualRightsMember / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember | 42 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_ContractualRightsMember / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember |
Franchises and Consents [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross | 15 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_FranchiseRightsMember | 15 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_FranchiseRightsMember | [1]
Finite-Lived Intangible Assets, Accumulated Amortization | 8 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_FranchiseRightsMember | 7 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_FranchiseRightsMember |
Franchises and Consents [Member] | Consumers Energy Company [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross | 15 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_FranchiseRightsMember / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember | 15 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_FranchiseRightsMember / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember | [1]
Finite-Lived Intangible Assets, Accumulated Amortization | 8 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_FranchiseRightsMember / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember | 7 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_FranchiseRightsMember / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember |
Other Intangibles [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross | 21 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_OtherIntangibleAssetsMember | 21 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_OtherIntangibleAssetsMember | [1]
Finite-Lived Intangible Assets, Accumulated Amortization | 14 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_OtherIntangibleAssetsMember | 14 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_OtherIntangibleAssetsMember |
Other Intangibles [Member] | Consumers Energy Company [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross | 21 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_OtherIntangibleAssetsMember / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember | 20 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_OtherIntangibleAssetsMember / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember | [1]
Finite-Lived Intangible Assets, Accumulated Amortization | $ 14 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_OtherIntangibleAssetsMember / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember | $ 14 us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_OtherIntangibleAssetsMember / dei_LegalEntityAxis = cms_ConsumersEnergyCompanyMember |
Minimum [Member] | Software and Software Development Costs [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 3 years |  |
Minimum [Member] | Software and Software Development Costs [Member] | Consumers Energy Company [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 3 years |  |
Minimum [Member] | Plant Acquisition Adjustments [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 15 years |  |
Minimum [Member] | Plant Acquisition Adjustments [Member] | Consumers Energy Company [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 15 years |  |
Minimum [Member] | Rights of Way [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 50 years |  |
Minimum [Member] | Rights of Way [Member] | Consumers Energy Company [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 50 years |  |
Minimum [Member] | Franchises and Consents [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 5 years |  |
Minimum [Member] | Franchises and Consents [Member] | Consumers Energy Company [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 5 years |  |
Maximum [Member] | Software and Software Development Costs [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 15 years |  |
Maximum [Member] | Software and Software Development Costs [Member] | Consumers Energy Company [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 15 years |  |
Maximum [Member] | Plant Acquisition Adjustments [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 46 years |  |
Maximum [Member] | Plant Acquisition Adjustments [Member] | Consumers Energy Company [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 46 years |  |
Maximum [Member] | Rights of Way [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 75 years |  |
Maximum [Member] | Rights of Way [Member] | Consumers Energy Company [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 75 years |  |
Maximum [Member] | Franchises and Consents [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 30 years |  |
Maximum [Member] | Franchises and Consents [Member] | Consumers Energy Company [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 30 years |  |
[1] | Net intangible asset additions for Consumers’ utility plant were $96 million during 2014 and $53 million during 2013 and primarily represented software development costs.

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- Definition Current year acquisitions of long-lived assets used in the normal conduct of business and not intended for resale. Examples include land, buildings, machinery and equipment, certain intangible assets, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software. + References No definition available. + Details
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