Derivative Instruments (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments
Company's derivative instruments recorded at fair value	1 year
Company's derivative instruments recorded at fair value
Total derivatives assets		$ 466
Not Designated as Hedging Instrument
Company's derivative instruments recorded at fair value
Total derivatives assets		466
Foreign currency option contracts | Not Designated as Hedging Instrument | Other current assets
Company's derivative instruments recorded at fair value
Total derivatives assets		$ 466