Derivative Financial Instruments Derivative Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Derivative, Notional Amount	$ 140,737	$ 121,930
Swedish kronor
Derivative, Notional Amount	97,650	99,214
British pound sterling
Derivative, Notional Amount	8,282	5,641
Australian dollar
Derivative, Notional Amount	3,402	5,986
Japanese yen
Derivative, Notional Amount	1,943	4,462
Euro
Derivative, Notional Amount	12,288	265
Canada, Dollars
Derivative, Notional Amount	13,588	2,914
Other
Derivative, Notional Amount	$ 3,584	$ 3,448