Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 12,982	$ 12,791	$ 8,667	$ 46,460
Other comprehensive income (loss)
Foreign currency translation adjustments, net of tax	8,575	(10,984)	7,237	(12,317)
Unrealized gain (loss) on interest rate swap, net of tax	716	(388)	(1,259)	(3,512)
Total other comprehensive income (loss)	9,291	(11,372)	5,978	(15,829)
Comprehensive income	$ 22,273	$ 1,419	$ 14,645	$ 30,631