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Leases (Schedule Of Lease Expenses Included In Consolidated Statements Of Income) (Details) - WPL [Member] - Sheboygan Falls Energy Facility [Member] - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Property, Plant and Equipment [Line Items] |  |  |
Interest expense | $ 9.9 | $ 10.4 | $ 10.9
Depreciation and amortization | 6.2 | 6.2 | 6.2
Total lease expenses included in income statements | $ 16.1 | $ 16.6 | $ 17.1

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- Definition The charge for the use of long-lived depreciable capital leased assets for the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 840 -Section 55 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6501752&loc=d3e56872-110439 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6455314&loc=d3e45031-112735 + Details
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- Definition The financing charge for leasing arrangements meeting the criteria for capitalization. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6455314&loc=d3e45031-112735 + 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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- Details
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