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Commitments And Contingencies (MPG Site Estimated Future Costs And Recorded Liabilities) (Details) - Manufactured Gas Plant [Member] $ in Millions | 9 Months Ended
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Sep. 30, 2025 USD ($)
Commitments and Contingencies [Line Items] |
Current and non-current environmental liabilities | $ 12
IPL [Member] |
Commitments and Contingencies [Line Items] |
Current and non-current environmental liabilities | 8
WPL [Member] |
Commitments and Contingencies [Line Items] |
Current and non-current environmental liabilities | 4
Minimum [Member] |
Commitments and Contingencies [Line Items] |
Range of estimated future costs | 7
Minimum [Member] | IPL [Member] |
Commitments and Contingencies [Line Items] |
Range of estimated future costs | 5
Minimum [Member] | WPL [Member] |
Commitments and Contingencies [Line Items] |
Range of estimated future costs | 2
Maximum [Member] |
Commitments and Contingencies [Line Items] |
Range of estimated future costs | 29
Maximum [Member] | IPL [Member] |
Commitments and Contingencies [Line Items] |
Range of estimated future costs | 18
Maximum [Member] | WPL [Member] |
Commitments and Contingencies [Line Items] |
Range of estimated future costs | $ 11

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- Definition Total costs accrued as of the balance sheet date for environmental loss contingencies. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483076/450-20-50-1 Reference 2: http://www.xbrl.org/2003/role/recommendedDisclosureRef -Topic 410 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 10 -Subparagraph (d)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481931/410-30-50-10 Reference 3: http://www.xbrl.org/2003/role/recommendedDisclosureRef -Topic 410 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 10 -Subparagraph (d)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481931/410-30-50-10 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 410 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 16 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481899/410-30-55-16 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 5.Y.Q1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480102/450-20-S99-1 Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 410 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481931/410-30-50-7 + Details
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- Definition Total anticipated costs associated with remediation, site restoration, postclosure, monitoring commitments, or other exit costs that may occur on the sale, disposal, or abandonment of a particular property resulting from unanticipated contamination of the assets. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 275 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482861/275-10-50-9 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 5.Y.Q4) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480102/450-20-S99-1 + Details
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