Derivative Instruments (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments
Forward contracts, designated as cash flow hedges, fair value liabilities	$ (2,169)	$ (6,018)
Cash flow hedge gain (loss) recognized in Accumulated Other Comprehensive Loss associated with foreign exchange rate forward contracts	$ (282)	$ 538	$ (287)

Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 10A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=28358780&loc=SL7669646-108580

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