Other Income (Expense), Net (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Summary of other income, net
Interest income	$ 686	$ 245	$ 1,734	$ 680
Net gain (loss) on foreign exchange and foreign currency derivative contracts	(495)	425	(2,247)	(507)
Net realized gain on sales of short-term investments	4	2	10	55
Other non-operating income (expense), net	(39)	0	99	0
Total other income (expense), net	$ 156	$ 672	$ (404)	$ 228