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Summary Of Significant Accounting Policies (Narrative) (Details) $ in Millions | Jun. 30, 2021 USD ($)
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WPL [Member] | Columbia Units 1 and 2 [Member] |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
Electric plant anticipated to be retired early | $ 475

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- Definition The present value amount of future cost recoveries that are probable and estimable related to plant abandonment's for regulated industries. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section 35 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6500292&loc=d3e45591-110387 + Details
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