Derivative Instruments - Foreign Currency Loss (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 29, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gain (Loss) Attributable To Foreign Exchange Rate Fluctuations, Inclusive Of The Impact Of Derivatives	$ (486)	$ (723)	$ (606)	$ (953)