Derivatives and Other Financial Instruments - Summary of derivatives on condensed consolidated financial statements of income (Details 1) (Foreign Currency Exchange Contracts, Other Expense: Gain (loss) on foreign currency exchange rate, Not designated as hedging instrument, USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Foreign Currency Exchange Contracts | Other Expense: Gain (loss) on foreign currency exchange rate | Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Derivatives, (Loss) Gain Recognized in Income	$ 3	$ (6)	$ 24	$ (13)