Goodwill and Other Intangible Assets Goodwill (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 24, 2017	Sep. 25, 2016	Dec. 31, 2016
Goodwill [Roll Forward]
Goodwill (gross), beginning of period	$ 259,528	$ 290,679	$ 290,679
Accumulated Impairment Losses, beginning of period	(79,868)	(79,868)	(79,868)
Goodwill (net), beginning of period	179,660	210,811	210,811
Foreign currency translation	5,350	4,649
Goodwill (gross), end of period	264,878	295,328	259,528
Accumulated Impairment Losses, ending of period	(79,868)	(79,868)	(79,868)
Goodwill (net), end of period	$ 185,010	$ 215,460	179,660
Adjustment to reduce goodwill and deferred tax liabilities			$ 33,900