XML 108 R61.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Regulatory Matters (Schedule Of The Components Of Regulatory Assets and Liabilities) (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2016 | Dec. 31, 2015
Public Utilities, General Disclosures [Line Items] |  |  |
Regulatory assets, current |  | $ 17 | $ 16
Regulatory assets, noncurrent |  | 2,091 | 1,840
Regulatory liabilities, current |  | 95 | 82
Regulatory liabilities, noncurrent |  | 2,041 | 2,088
Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Regulatory assets, current |  | 17 | 16
Regulatory assets, noncurrent |  | 2,091 | 1,840
Total regulatory asset |  | 2,108 | 1,856
Regulatory liabilities, current |  | 95 | 82
Regulatory liabilities, noncurrent |  | 2,041 | 2,088
Total regulatory liabilities |  | 2,136 | 2,170
Cost Of Removal [Member] | Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Regulatory liabilities, noncurrent |  | $ 1,809 | 1,745
Renewable Energy Plan [Member] | Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Noncurrent Regulatory Liability, Recovery End Date |  | 2028 |
Regulatory liabilities, noncurrent |  | $ 83 | 109
Income Taxes, Net [Member] | Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Current Regulatory Liability Recovery End Date |  | 2017 |
Regulatory liabilities, current |  | $ 64 | 64
Regulatory liabilities, noncurrent |  | 7 | 64
ARO [Member] | Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Regulatory liabilities, noncurrent |  | $ 62 | 73
Renewable Energy Grant [Member] | Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Noncurrent Regulatory Liability, Recovery End Date |  | 2043 |
Regulatory liabilities, noncurrent |  | $ 58 | 60
Energy Optimization [Member] | Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Noncurrent Regulatory Asset Recovery End Date |  | 2018 |
Regulatory assets, noncurrent |  | $ 18 | 18
Regulatory liabilities, noncurrent |  | 11 | 26
Other Regulatory Assets [Member] | Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Regulatory liabilities, noncurrent |  | $ 11 | 11
Revenue Subject To Refund [Member] | Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Current Regulatory Liability Recovery End Date |  | 2017 |
Regulatory liabilities, current |  | $ 31 | 18
Postretirement Benefits [Member] | Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Regulatory assets, noncurrent | [1] | $ 1,373 | 1,096
Securitized Costs [Member] | Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Noncurrent Regulatory Asset Recovery End Date | [2] | 2029 |
Regulatory assets, noncurrent | [2] | $ 323 | 348
Manufactured Gas Plant [Member] | Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Regulatory assets, noncurrent | [1] | 139 | 146
ARO [Member] | Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Regulatory assets, noncurrent |  | 166 | 151
Unamortized Loss On Reacquired Debt [Member] | Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Regulatory assets, noncurrent |  | 54 | 61
Gas Storage Inventory Adjustments [Member] | Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Regulatory assets, noncurrent | [3] | $ 14 | 18
Energy Optimization [Member] | Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Regulatory Current Asset, End Date for Recovery | [4] | 2017 |
Regulatory assets, current | [4] | $ 17 | 16
Other Regulatory Assets [Member] | Consumers Energy Company [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Regulatory assets, noncurrent |  | $ 4 | $ 2
[1] | The MPSC has authorized a specific return on this regulatory asset.
[2] | This regulatory asset is offset partially by liabilities. The net amount is included in rate base, thereby providing a return.
[3] | These regulatory assets represent incurred costs for which the MPSC has provided, or Consumers expects, recovery without a return on investment.
[4] | These regulatory assets have arisen from an alternative revenue program and are not associated with incurred costs or capital investments. Therefore, the MPSC has provided for recovery without a return.

X
- Definition The end date for recovery of the individual regulatory current liability in a schedule of regulatory current liabilities. + References No definition available. + Details
Name: | cms_CurrentRegulatoryLiabilityRecoveryEndDate
Namespace Prefix: | cms_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

X
- Definition The end date for recovery of the individual regulatory noncurrent asset in a schedule of regulatory noncurrent assets. + References No definition available. + Details
Name: | cms_NoncurrentRegulatoryAssetRecoveryEndDate
Namespace Prefix: | cms_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

X
- Definition Noncurrent Regulatory Liability, Recovery End Date + References No definition available. + Details
Name: | cms_NoncurrentRegulatoryLiabilityRecoveryEndDate
Namespace Prefix: | cms_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesGeneralDisclosuresLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 + Details
Name: | us-gaap_RegulatoryAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer. Such costs are capitalized if they meet both of the following criteria: a. It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b. Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs. If the revenue will be provided through an automatic rate-adjustment clause, this criterion requires that the regulator's intent clearly be to permit recovery of the previously incurred cost. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 + Details
Name: | us-gaap_RegulatoryAssetsCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 + Details
Name: | us-gaap_RegulatoryAssetsNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The end date for recovery of the individual regulatory current asset in a schedule of regulatory current assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 + Details
Name: | us-gaap_RegulatoryCurrentAssetEndDateForRecovery
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount for the individual regulatory liability as itemized in a table of regulatory liabilities as of the end of the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 405 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6500807&loc=d3e48068-110394 + Details
Name: | us-gaap_RegulatoryLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount for the individual regulatory current liability as itemized in a table of regulatory current liabilities as of the end of the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 405 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6500807&loc=d3e48068-110394 + Details
Name: | us-gaap_RegulatoryLiabilityCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount for the individual regulatory noncurrent liability as itemized in a table of regulatory noncurrent liabilities as of the end of the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.24) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_RegulatoryLiabilityNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | dei_LegalEntityAxis=cms_ConsumersEnergyCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=us-gaap_RemovalCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=us-gaap_RenewableEnergyProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=us-gaap_DeferredIncomeTaxChargesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=us-gaap_AssetRetirementObligationCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=cms_RenewableEnergyGrantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=cms_EnergyOptimizationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=us-gaap_OtherRegulatoryAssetsLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=us-gaap_RevenueSubjectToRefundMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_PostretirementBenefitCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=cms_SecuritizedCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=cms_ManufacturedGasPlantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_AssetRetirementObligationCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_LossOnReacquiredDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=cms_GasStorageInventoryAdjustmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=cms_EnergyOptimizationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_OtherRegulatoryAssetsLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |