Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Total
Balance, at Dec. 29, 2018	$ 9,949	$ 1,163,545	$ 262	$ (150,857)	$ 1,022,899
Balance, shares at Dec. 29, 2018	33,047,807			6,149,364
Net income		14,304			14,304
Other comprehensive income (loss), net of reclassification adjustments and tax			621		621
Dividends paid		(8,339)			(8,339)
Balance, at Mar. 30, 2019	$ 9,949	1,169,510	883	$ (150,857)	1,029,485
Balance, shares at Mar. 30, 2019	33,047,807			6,149,364
Balance, at Dec. 28, 2019	$ 9,949	1,198,173	1,480	$ (150,857)	1,058,745
Balance, shares at Dec. 28, 2019	33,047,807			6,149,364
Net income		26,689			26,689
Other comprehensive income (loss), net of reclassification adjustments and tax			89		89
Dividends paid		(8,339)			(8,339)
Balance, at Mar. 28, 2020	$ 9,949	$ 1,216,524	$ 1,569	$ (150,857)	$ 1,077,185
Balance, shares at Mar. 28, 2020	33,047,807			6,149,364