Derivative Instruments (Details 1) (Designated as Hedging Instrument [Member], USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset (short-term)	$ 2,274	$ 830
Derivative asset (long-term)	305
Derivative liability (short-term)	$ (445)