Derivative Financial Instruments Derivative Instruments Not Designated as Hedges (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Other income, net	$ (879)	$ 15	$ (197)	$ 999
Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	(691)	(1,088)	(1,510)	(2,233)
Not Designated as Hedging Instrument [Member] | Cross-currency swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense, net	(717)	(1,203)	(1,532)	(2,521)
Other income, net	$ 26	$ 115	$ 22	$ 288