v3.25.4

Retirement Benefits (Schedule of Retirement Benefit Plan Assets (Liabilities)) (Details) - USD ($) $ in Millions | Dec. 31, 2025 | Dec. 31, 2024
--- | --- | ---
Defined Benefit Plan Disclosure [Line Items] |  |
Non-current assets | $ 1,957 | $ 1,627
Non-current liabilities | 95 | 96
Consumers Energy Company |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Non-current assets | 1,821 | 1,514
Non-current liabilities | 70 | 70
DB Pension Plans |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Non-current assets | 1,054 | 870
DB Pension Plans | Consumers Energy Company |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Non-current assets | 1,009 | 836
OPEB Plan |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Non-current assets | 903 | 757
OPEB Plan | Consumers Energy Company |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Non-current assets | 812 | 678
DB SERP |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Current liabilities | 10 | 10
Non-current liabilities | 94 | 95
DB SERP | Consumers Energy Company |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Current liabilities | 7 | 7
Non-current liabilities | $ 69 | $ 69

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