Pensions and Other Postretirement Benefit Plans (Schedule of Amounts That Will Be Amortized from Accumulated Other Comprehensive Income) (Details) $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Actuarial loss	$ 2,578
Prior service cost/(benefit)	38
Total	2,616
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Actuarial loss	2,811
Prior service cost/(benefit)	(4,488)
Total	$ (1,677)

Amount included in accumulated other comprehensive income (AOCI) expected to be recognized as components of net periodic benefit cost for the fiscal year that follows the most recent annual statement of financial position, including gain (loss), prior service cost (credit), and transition asset (obligation).

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration