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Derivative and Hedging Instruments (Details-4) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018
Current and Long-Term Regulatory Asset [Member] |  |
Change in Derivative Fair Value [Roll Forward] |  |
Beginning balance | $ 31,830 | $ 41,958
Unrealized (gain) loss | (5,493) | (11,094)
Realized (loss) gain reclassified to a deferred account | (1,896) | 523
Realized gain (loss) reclassified to income statement | 2,434 | 443
Ending balance | 26,875 | 31,830
Other Current Assets [Member] |  |
Change in Derivative Fair Value [Roll Forward] |  |
Beginning balance | 377 | 806
Unrealized (gain) loss | 0 | 0
Realized (loss) gain reclassified to a deferred account | 1,896 | (523)
Realized gain (loss) reclassified to income statement | (1,173) | 94
Ending balance | $ 1,100 | $ 377

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- Definition Fair value of the assets less the liabilities of a derivative or group of derivatives. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13433-108611 + Details
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- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959 + Details
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- Definition The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585 + Details
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