Derivatives - Fair Value (Details) (Fair value measurements, recurring, Foreign currency exchange futures contracts, Not designated as hedging instrument, USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
(Level 1)
Derivatives, Fair Value [Line Items]
Foreign currency exchange futures contracts fair value	$ 0	$ 0
(Level 2)
Derivatives, Fair Value [Line Items]
Foreign currency exchange futures contracts fair value	509	(13)
(Level 3)
Derivatives, Fair Value [Line Items]
Foreign currency exchange futures contracts fair value	0	0
Estimate of fair value
Derivatives, Fair Value [Line Items]
Foreign currency exchange futures contracts fair value	$ 509	$ (13)