Derivative Agreements (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended	1 Months Ended		6 Months Ended			6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2011 Interest rate swap agreement	May 31, 2012 Interest rate swap agreement Senior secured credit facility	Jul. 31, 2011 Interest rate swap agreement Senior secured credit facility agreement	Jun. 30, 2013 Foreign currency derivative contracts	Jun. 30, 2012 Foreign currency derivative contracts	Dec. 31, 2012 Foreign currency derivative contracts	Jun. 30, 2013 Foreign currency derivative Argentine Peso to U.S. dollar, maturing September 30, 2013	Jun. 30, 2013 Foreign currency derivative Argentine Peso to U.S. dollar, maturing December 31, 2013	Jun. 30, 2013 Foreign currency derivative Argentine Peso to U.S. dollar, maturing March 31, 2014
Derivative Agreements
Fair value of interest rate hedge at time of termination					$ 1,900,000	$ 1,000,000
Ineffectiveness recorded as a result of termination of the interest rate swap agreement					0	0
Amortization of loss related to termination of interest rate swap				958,000	84,000	1,000,000
Number of agreements entered							2
Notional amount of the swap agreement							116,000,000
Interest rate exposure, fixed portion (as a percent)							0.923%
Margin added to fixed interest rate (as a percent)							4.75%
Percentage of forecasted operating income targeted to cover over next twelve months through the use of forward contracts								70.00%
Maturity period of derivative instruments								12 months
Loss relating to fair market valuation	190,000	(374,000)	242,000	220,000				200,000	200,000
Foreign Currency Derivative Agreement
Notional Amount								3,750,000			1,250,000	1,250,000	1,250,000
Premium Amount								409,000			111,000	127,000	171,000
Fair Value								$ 247,000		$ 300,000	$ 37,000	$ 101,000	$ 109,000