Debt (Financing Liability) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2016	Mar. 29, 2015	Mar. 30, 2014	Dec. 27, 2015
Debt Instrument [Line Items]
Current portion of financing liability	$ 21,285			$ 20,891
Other operating income	0	$ 361
Financing Agreement June 2011 | SPAIN
Debt Instrument [Line Items]
Financing liability	$ 32,900			$ 31,700
Financing arrangement, imputed interest on financing liability	6.365%
Financing arrangement, interest expense recognized	$ 500		$ 500
Financing Agreement 2015 | SPAIN
Debt Instrument [Line Items]
Financing liability		$ 1,100