Inventories (Components Of Inventory) (Details) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Finished goods	$ 113,220	$ 102,056
Raw materials	31,258	32,095
Maintenance parts, packaging and supplies	45,411	39,305
Total inventories, net	$ 189,889	$ 173,456