Derivative Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 Foreign currency exchange forwards	Mar. 31, 2012 Foreign currency exchange forwards	Mar. 31, 2013 Not Designated as Hedges	Dec. 31, 2012 Not Designated as Hedges	Mar. 31, 2013 Not Designated as Hedges Foreign currency exchange forwards	Dec. 31, 2012 Not Designated as Hedges Foreign currency exchange forwards
Derivative financial instruments
Notional amount of derivative instruments					$ 3,715	$ 9,590	$ 3,715	$ 9,590
Estimated Fair value of derivative instruments					(21)	244	(21)	244
Amount of Realized Net (Loss) Gain and Changes in the Fair Value of Derivatives			228	80
Weighted average notional amount of derivatives outstanding	$ 2,400	$ 2,405