Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Dec. 29, 2018
Changes in the carrying amount of goodwill
Balance at the beginning of the period, Goodwill gross	$ 164,625
Effects of foreign currency translation	(395)
Balance at the end of the period, Goodwill gross	164,230
Balance at the beginning of the period, Accumulated impairment losses	(76,417)
Balance at the end of the period, Accumulated impairment losses	(76,417)
Goodwill, net	87,813		$ 88,208
Balance at the end of the period, Goodwill, net	87,813
Intangible assets impairment losses	$ 0	$ 0