Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 24, 2018
Goodwill [Roll Forward]
Goodwill (gross), beginning of period	$ 258,587	$ 263,698
Accumulated Impairment Losses, beginning of period	(79,868)	(79,868)
Goodwill (net), beginning of period	178,719	183,830
Foreign currency translation	2,480	(3,644)
Goodwill (gross), end of period	261,067	260,054
Accumulated Impairment Losses, ending of period	(79,868)	(79,868)
Goodwill (net), end of period	$ 181,199	$ 180,186