Summary Of Significant Accounting Policies (Components of Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, December 28, 2014			$ (34,684)
Foreign currency translation adjustment			(18,635)
Amounts reclassified from other comprehensive income			2,230
Net other comprehensive income (loss)	$ (6,479)	$ (10,554)	(16,405)	$ (9,124)
Balance, September 27, 2015	(51,089)		(51,089)
Pension plan
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, December 28, 2014			(35,036)
Foreign currency translation adjustment			2,823
Amounts reclassified from other comprehensive income			2,230
Net other comprehensive income (loss)			5,053
Balance, September 27, 2015	(29,983)		(29,983)
Foreign currency translation adjustment
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, December 28, 2014			352
Foreign currency translation adjustment			(21,458)
Amounts reclassified from other comprehensive income			0
Net other comprehensive income (loss)			(21,458)
Balance, September 27, 2015	$ (21,106)		$ (21,106)