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Contingencies and Commitments (Summary of Guarantees) (Details) $ in Millions | Sep. 30, 2025 USD ($)
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Variable Interest Entity, Primary Beneficiary | Aviator Wind Equity Holdings |
Guarantees And Other Contingencies [Line Items] |
Ownership percentage | 49.00%
Guarantees |
Guarantees And Other Contingencies [Line Items] |
Maximum Obligation | $ 30
Carrying Amount | 0
Guarantees | Consumers Energy Company |
Guarantees And Other Contingencies [Line Items] |
Maximum Obligation | 30
Carrying Amount | 0
Indemnity obligations from sale of membership interests in VIEs |
Guarantees And Other Contingencies [Line Items] |
Maximum Obligation | 229
Carrying Amount | 0
Indemnity obligations from stock and asset sale agreements |
Guarantees And Other Contingencies [Line Items] |
Maximum Obligation | 152
Carrying Amount | $ 0

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- Definition The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 460 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482425/460-10-50-4 + Details
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- Definition Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 460 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482425/460-10-50-4 + Details
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