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Summary Of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Regulatory Assets [Line Items] |  |  |
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense | $ 0 | $ 0 | $ 0
AFUDC Above FERC Allowed Rate [Member] |  |  |
Regulatory Assets [Line Items] |  |  |
Reclassification of Prior Year Amounts to Comply with Regulatory Requirements | $ 33,000 |  |

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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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- Definition Amount of expense for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319 + Details
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