General (Details 2) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments
Period for which certain forecasted foreign currency rent and salary payments are hedged			12 months
Notional amount of foreign currency forward contracts and options outstanding	$ 7,700,000		$ 7,700,000
Net fair value balance of foreign currency forward contracts and options outstanding	300,000		300,000
Fair value asset balance of foreign currency forward contracts and options outstanding	300,000		300,000
Fair value liability balance of foreign currency forward contracts and options outstanding	0		0
Period expected to be recognized in results of operations			12 months
Hedging gain (loss) recognized in operations	214,000	(302,000)	695,000	(542,000)
Amount of cash in bank accounts with the counterparty the entity has agreed to maintain	$ 1,700,000		$ 1,700,000