Derivative Instruments (Details 1) (Energy contracts and options [Member], USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Other current assets [Member]
Schedule of fair value of outstanding derivative instruments recorded as assets and liability
Asset Derivatives, not designated or not qualifying as hedging instruments	$ 857	$ 1,682
Other current liabilities [Member]
Schedule of fair value of outstanding derivative instruments recorded as assets and liability
Liability Derivatives, not designated or not qualifying as hedging instruments	$ 391	$ 385

Fair value as of the balance sheet date of derivative instrument not designated as hedging instrument and classified as a liability.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4B

-Subparagraph (c)(2)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624163-113959

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant