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Regulatory Matters (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2024 | Sep. 30, 2023
Regulatory Matters [Line Items] |  |  |  |
Asset valuation charge for IPL's Lansing Generating Station | $ 0 | $ 0 | $ 60 | $ 0
IPL [Member] |  |  |  |
Regulatory Matters [Line Items] |  |  |  |
Asset valuation charge for IPL's Lansing Generating Station | $ 0 | $ 0 | 60 | $ 0
October 2024 Through September 2025 Test Period Retail Electric [Member] | IPL [Member] |  |  |  |
Regulatory Matters [Line Items] |  |  |  |
Authorized increase (decrease) in final rates, amount |  |  | 185 |
October 2024 Through September 2025 Test Period Retail Gas [Member] | IPL [Member] |  |  |  |
Regulatory Matters [Line Items] |  |  |  |
Authorized increase (decrease) in final rates, amount |  |  | $ 10 |

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- Definition Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-28 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482130/360-10-45-4 + Details
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- Definition Amount of public utility's approved rate increase (decrease) by regulatory agency. + References No definition available. + Details
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