Other Income (Expense), Net (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Summary of other income, net
Interest income	$ 578	$ 233	$ 1,048	$ 435
Net loss on foreign exchange and foreign currency derivative contracts	(819)	(954)	(1,752)	(932)
Net realized gain on sales of short-term investments	3	53	6	53
Other non-operating income (expense), net	(14)	0	138	0
Total other income (expense), net	$ (252)	$ (668)	$ (560)	$ (444)