Other Operating (Income) Expenses, net (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Operating (Income) Expenses, net [Abstract]
Gain on sale of operating assets	$ (1)us-gaap_GainLossOnSaleOfOtherAssets	$ (65)us-gaap_GainLossOnSaleOfOtherAssets	$ (27)us-gaap_GainLossOnSaleOfOtherAssets
Frozen defined-benefit pension plan (income) expense	(1,611)	(336)	320
Total other operating (income) expenses, net	$ (1,612)us-gaap_OtherOperatingIncomeExpenseNet	$ (401)us-gaap_OtherOperatingIncomeExpenseNet	$ 293us-gaap_OtherOperatingIncomeExpenseNet

Amount of gain (loss) on sale or disposal of other assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Name:	us-gaap_GainLossOnSaleOfOtherAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration