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Summary Of Significant Accounting Policies (Reclassifications Out of Accumulated Other Comprehensive Loss) (Details) - Reclassification Out of Accumulated Other Comprehensive Income [Member] - Accumulated Defined Benefit Plans Adjustment [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Amortization of net prior service cost	$ (228)	$ (299)	$ (456)	$ (598)
Amortization of net loss	2,995	3,638	5,990	7,276
Adjustment due to effects of regulation	(2,509)	(3,057)	(5,017)	(6,115)
Total before tax	258	282	517	563
Tax benefit (expense)	(54)	(99)	(109)	(197)
Net of tax	$ 204	$ 183	$ 408	$ 366

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Amount, before tax, of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) of defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
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