XML 71 R54.htm IDEA: XBRL DOCUMENT
v3.21.2

Variable Interest Entities (Narrative) (Details) $ in Millions | 9 Months Ended |
--- | --- | ---
Sep. 30, 2021 USD ($) MW | Dec. 31, 2020 USD ($)
Variable Interest Entity [Line Items] |  |
Investments | $ 73 | $ 70
Variable Interest Entity, Primary Beneficiary | Aviator Wind |  |
Variable Interest Entity [Line Items] |  |
Ownership interest | 51.00% |
Nameplate capacity (in MW) | MW | 525 |
Variable Interest Entity, Primary Beneficiary | Aviator Wind Class B Membership |  |
Variable Interest Entity [Line Items] |  |
Noncontrolling ownership interest | 49.00% |
Variable Interest Entity, Not Primary Beneficiary |  |
Variable Interest Entity [Line Items] |  |
Investments | $ 73 | $ 70
Variable Interest Entity, Not Primary Beneficiary | T.E.S. Filer City |  |
Variable Interest Entity [Line Items] |  |
Ownership interest | 50.00% |
Variable Interest Entity, Not Primary Beneficiary | Grayling |  |
Variable Interest Entity [Line Items] |  |
Ownership interest | 50.00% |
Variable Interest Entity, Not Primary Beneficiary | Genesee |  |
Variable Interest Entity [Line Items] |  |
Ownership interest | 50.00% |
Variable Interest Entity, Not Primary Beneficiary | Craven |  |
Variable Interest Entity [Line Items] |  |
Ownership interest | 50.00% |

X
- Definition Variable Interest Entity, Maximum Capacity + References No definition available. + Details
Name: | cms_VariableInterestEntityMaximumCapacity
Namespace Prefix: | cms_
Data Type: | dtr-types:powerItemType
Balance Type: | na
Period Type: | duration

X
- Definition This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=109237563&loc=d3e33749-111570 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 25 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8813-108599 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_EquityMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity. + References No definition available. + Details
Name: | us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

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_VariableInterestEntityLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 5A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=123419778&loc=SL6759159-111685 + Details
Name: | us-gaap_VariableInterestEntityOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_OwnershipAxis=cms_AviatorWindMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_OwnershipAxis=cms_AviatorWindClassBMembershipMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_OwnershipAxis=cms_TESFilerCityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_OwnershipAxis=cms_GraylingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_OwnershipAxis=cms_GeneseeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_OwnershipAxis=cms_CravenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |