Retirement Benefits (Schedule of Expected Benefit Payments) (Details) $ in Millions	Dec. 31, 2025 USD ($)
DB Pension Plans
Defined Benefit Plan Disclosure [Line Items]
2026	$ 164
2027	165
2028	164
2029	164
2030	164
2031-2035	801
DB Pension Plans \| Consumers Energy Company
Defined Benefit Plan Disclosure [Line Items]
2026	154
2027	155
2028	154
2029	155
2030	154
2031-2035	756
DB SERP
Defined Benefit Plan Disclosure [Line Items]
2026	10
2027	10
2028	10
2029	9
2030	9
2031-2035	41
DB SERP \| Consumers Energy Company
Defined Benefit Plan Disclosure [Line Items]
2026	7
2027	7
2028	7
2029	6
2030	6
2031-2035	29
OPEB Plan
Defined Benefit Plan Disclosure [Line Items]
2026	59
2027	61
2028	62
2029	62
2030	62
2031-2035	305
OPEB Plan \| Consumers Energy Company
Defined Benefit Plan Disclosure [Line Items]
2026	57
2027	58
2028	59
2029	59
2030	60
2031-2035	$ 292

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.

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