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Business Segment Information: Capital Expenditures and Asset Acquisitions (Details) - USD ($) $ in Millions | 9 Months Ended
--- | ---
Sep. 30, 2025 | Sep. 30, 2024
Segment Reporting Information [Line Items] |  |
Capital Expenditures | $ 608.5 | $ 565.8
Corporate, Non-Segment |  |
Segment Reporting Information [Line Items] |  |
Capital Expenditures | 6.9 | 10.8
Electric Utilities | Operating Segments |  |
Segment Reporting Information [Line Items] |  |
Capital Expenditures | 334.0 | 246.8
Gas Utilities | Operating Segments |  |
Segment Reporting Information [Line Items] |  |
Capital Expenditures | $ 267.6 | $ 308.2

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- Definition Amount of increase (decrease) of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. + References No definition available. + Details
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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 No definition available. + Details
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