Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2018	Sep. 27, 2017	Sep. 26, 2018	Sep. 27, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 10,805	$ 9,325	$ 32,190	$ 26,447
Other comprehensive income, net of tax:
Minimum pension liability adjustment, net of tax of $7, $9, $20 and $27, respectively	21	14	64	42
Recognition of unrealized gain (loss) on hedge transactions, net of tax of $1,583, $133, $1,673 and $(1,249), respectively	4,537	209	4,793	(1,958)
Other comprehensive income (loss)	4,558	223	4,857	(1,916)
Total comprehensive income	$ 15,363	$ 9,548	$ 37,047	$ 24,531