v3.25.4

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2026	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Tax Benefits [Line Items]
Deferred income taxes and investment tax credits		$ 202	$ 142	$ 157
Local Tax Authority
Income Tax Benefits [Line Items]
Valuation allowance - loss carryforward		2
Consumers Energy Company
Income Tax Benefits [Line Items]
Deferred income taxes and investment tax credits		48	$ 115	$ 156
2024 Renewable Energy Tax Credits
Income Tax Benefits [Line Items]
Deferred income taxes and investment tax credits		13
2025 Renewable Energy Tax Credits | Forecast
Income Tax Benefits [Line Items]
Deferred income taxes and investment tax credits	$ 32
2025 Renewable Energy Tax Credits | Consumers Energy Company
Income Tax Benefits [Line Items]
Deferred income taxes and investment tax credits		$ 36
2025 Renewable Energy Tax Credits | Consumers Energy Company | Forecast
Income Tax Benefits [Line Items]
Deferred income taxes and investment tax credits	$ 10

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- Definition

Income Tax Benefits [Line Items]

+ References

No definition available.

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Amount of deferred income tax expense (benefit) and income tax credits.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

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- Definition

The portion of the valuation allowance pertaining to the deferred tax asset representing potential future taxable deductions from net operating loss carryforwards for which it is more likely than not that a tax benefit will not be realized.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

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