Derivative Financial Instruments (Details 4) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Other income, net	$ 984	$ 568
Derivative instruments not designated as hedging instruments, gain (loss), net	(1,145)	(1,414)
Cross-currency swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest (expense)/income	(1,318)	(1,436)
Other income, net	$ 173	$ 22