Derivative Instruments - Foreign Currency Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gain (Loss) Attributable To Foreign Exchange Rate Fluctuations, Inclusive Of The Impact Of Derivatives	$ (1,309)	$ (644)	$ (1,915)	$ (1,597)