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v3.25.3

Property, Plant and Equipment (Narrative) (Details) $ in Millions | Sep. 30, 2025 USD ($) MW
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Columbia Units 1 and 2 |
Property, Plant and Equipment [Line Items] |
Net book value, Columbia Units 1 and 2 | $ 398
WPL [Member] |
Property, Plant and Equipment [Line Items] |
Electric capacity of solar project | MW | 1,100
Construction project cost target, exceedance | $ 205
WPL [Member] | Columbia Units 1 and 2 |
Property, Plant and Equipment [Line Items] |
Net book value, Columbia Units 1 and 2 | $ 398

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- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 7A -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478964/842-20-50-7A + Details
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