Income Taxes (Summary of Loss and Credit Carryforwards) (Details) $ in Millions	Dec. 31, 2024 USD ($)
Operating Loss Carryforwards [Line Items]
General business credits	$ 216
Total tax attributes	258
Consumers Energy Company
Operating Loss Carryforwards [Line Items]
General business credits	8
Total tax attributes	37
Michigan State Tax Authority
Operating Loss Carryforwards [Line Items]
Local net operating loss carryforwards	38
Michigan State Tax Authority \| Consumers Energy Company
Operating Loss Carryforwards [Line Items]
Local net operating loss carryforwards	29
Arkansas State Tax Authority
Operating Loss Carryforwards [Line Items]
Local net operating loss carryforwards	2
Local Tax Authority
Operating Loss Carryforwards [Line Items]
Local net operating loss carryforwards	$ 2

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards and deductible tax credit carryforwards including, but not limited to, research, foreign, general business, alternative minimum tax, and other deductible tax credit carryforwards.

No definition available.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible state and local operating loss carryforwards.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-6

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible general business tax credit carryforwards.

+ References

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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-3

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