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Property, Plant and Equipment (Narrative) (Details) - WPL [Member] $ in Millions | 6 Months Ended
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Jun. 30, 2024 USD ($) lease_renewal_period_option MW
Property, Plant and Equipment [Line Items] |
Electric capacity of solar project | MW | 1,100
Construction project cost target exceedance | $ 195
Sheboygan Falls Energy Facility |
Property, Plant and Equipment [Line Items] |
Financing lease, lease renewal periods remaining | lease_renewal_period_option | 0
West Riverside Energy Center [Member] |
Property, Plant and Equipment [Line Items] |
Ownership interest, percent | 56.60%
Electric Generation | Edgewater Unit 5 |
Property, Plant and Equipment [Line Items] |
Net book value, Edgewater Unit 5 | $ 496
Utility electric generation plant in service, Edgewater Unit 5 | $ 806

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