Pension and Postretirement Plans (Future Amortization of Net Periodic Cost) (Details 8) $ in Thousands	Dec. 31, 2017 USD ($)
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Actuarial (gain) loss recognition	$ (4,236)
Prior service cost (credit) recognition	148
Supplemental Executive Retirement Plan (SERP) [Member]
Defined Benefit Plan Disclosure [Line Items]
Actuarial (gain) loss recognition	2,217
Prior service cost (credit) recognition	311
Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Actuarial (gain) loss recognition	(3,686)
Prior service cost (credit) recognition	$ (175)

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.

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Amount included in accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan expected to be recognized in net periodic benefit (cost) credit for fiscal year following most recent annual statement of financial position.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (s)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

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Amount included in accumulated other comprehensive (income) loss for prior service cost (credit) expected to be recognized in net periodic benefit cost (credit) for fiscal year following most recent annual statement of financial position.

+ References

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