v3.25.4

Regulatory Matters (Schedule of Regulatory Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Public Utilities, General Disclosures [Line Items]
Total current regulatory assets	$ 104	$ 229
Total non-current regulatory assets	3,355	3,569
Total current regulatory liabilities	85	111
Total non-current regulatory liabilities	4,091	4,067
Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total current regulatory assets	104	229
Total non-current regulatory assets	3,355	3,569
Total regulatory assets	3,459	3,798
Total current regulatory liabilities	85	111
Total non-current regulatory liabilities	4,091	4,067
Total regulatory liabilities	4,176	4,178
Income taxes, net | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total current regulatory liabilities	47	53
Total non-current regulatory liabilities	1,118	1,163
ASP gain | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total current regulatory liabilities	28	47
Total non-current regulatory liabilities	19	46
Other | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total current regulatory liabilities	10	11
Total non-current regulatory liabilities	40	24
Cost of removal | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory liabilities	2,727	2,665
Energy waste reduction plan | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory liabilities	68	41
Green Giving Program | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory liabilities	41	0
Postretirement benefits expense deferral mechanism | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory liabilities	40	37
Renewable energy grant | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory liabilities	38	40
Renewable Energy Plan | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory liabilities	0	51
Energy waste reduction plan incentive | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total current regulatory assets	66	60
Total non-current regulatory assets	64	64
Retention incentive program | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total current regulatory assets	10	18
Total non-current regulatory assets	6	12
2022 PSCR underrecovery | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total current regulatory assets	0	126
Other | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total current regulatory assets	28	25
Total non-current regulatory assets	54	25
Costs of coal-fueled electric generating units to be retired | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	1,179	1,266
Postretirement benefits | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	589	747
Securitized costs | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	549	666
ARO | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	379	366
Decommissioning costs | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	197	158
Unamortized loss on reacquired debt | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	89	92
MGP sites | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	82	90
Ludington overhaul contract dispute | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	60	31
Service restoration cost deferral | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	52	0
Energy waste reduction plan | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	26	31
Postretirement benefits expense deferral mechanism | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	22	21
Renewable Energy Plan | Consumers Energy Company
Public Utilities, General Disclosures [Line Items]
Total non-current regulatory assets	$ 7	$ 0

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://fasb.org/us-gaap/role/ref/legacyRef
-Topic 980
-SubTopic 340
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478742/980-340-50-1

+ 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://fasb.org/us-gaap/role/ref/legacyRef
-Topic 980
-SubTopic 340
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478742/980-340-50-1

+ 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://fasb.org/us-gaap/role/ref/legacyRef
-Topic 980
-SubTopic 340
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478742/980-340-50-1

+ Details

Name:	us-gaap_RegulatoryAssetsNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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://fasb.org/us-gaap/role/ref/legacyRef
-Topic 980
-SubTopic 405
-Name Accounting Standards Codification
-Section 25
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477571/980-405-25-1

+ 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://fasb.org/us-gaap/role/ref/legacyRef
-Topic 980
-SubTopic 405
-Name Accounting Standards Codification
-Section 25
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477571/980-405-25-1

+ 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://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(24))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ 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_DeferredIncomeTaxChargesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RegulatoryLiabilityAxis=cms_DeferredGainLossOnDisposalOfBusinessMember
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_RemovalCostsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RegulatoryLiabilityAxis=cms_EnergyWasteReductionPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RegulatoryLiabilityAxis=cms_GreenGivingProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RegulatoryLiabilityAxis=cms_PostretirementBenefitsExpenseDeferralMechanismMember
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=us-gaap_RenewableEnergyProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RegulatoryAssetAxis=cms_EnergyWasteReductionPlanIncentiveMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RegulatoryAssetAxis=cms_RetentionIncentiveProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RegulatoryAssetAxis=cms_A2022PowerSupplyRecoveryUnderrecoveryMember
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:

X

- Details

Name:	us-gaap_RegulatoryAssetAxis=cms_CoalFueledElectricGeneratingUnitsToBeRetiredMember
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=us-gaap_AssetRetirementObligationCostsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RegulatoryAssetAxis=cms_DecommissioningCostsMember
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_ManufacturedGasPlantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RegulatoryAssetAxis=cms_LudingtonPlantOverhaulContractDisputeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RegulatoryAssetAxis=cms_ServiceRestorationCostDeferralApplicationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RegulatoryAssetAxis=cms_EnergyWasteReductionPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RegulatoryAssetAxis=cms_PostretirementBenefitsExpenseDeferralMechanismMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RegulatoryAssetAxis=us-gaap_RenewableEnergyProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: