Derivative Instruments (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
Derivative Instruments
Company's derivative instruments recorded at fair value	1 year
Company's derivative instruments recorded at fair value
Total derivatives assets	$ 216
Total derivatives liability	62
Not Designated as Hedging Instrument
Company's derivative instruments recorded at fair value
Total derivatives assets	216
Total derivatives liability	62
Foreign currency option contracts | Not Designated as Hedging Instrument | Prepaid expenses and other current assets
Company's derivative instruments recorded at fair value
Total derivatives assets	216
Foreign currency option contracts | Not Designated as Hedging Instrument | Accrued liabilities
Company's derivative instruments recorded at fair value
Total derivatives liability	$ 62