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. 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, 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
Balance, at Dec. 26, 2020	$ 9,949	1,283,737	3,286	$ (150,857)	1,146,115
Balance, shares at Dec. 26, 2020	33,047,807			6,149,364
Net income		24,255			24,255
Other comprehensive income, net of reclassification adjustments and tax			(774)		(774)
Dividends paid		(8,339)			(8,339)
Balance, at Mar. 27, 2021	$ 9,949	$ 1,299,653	$ 2,512	$ (150,857)	$ 1,161,257
Balance, shares at Mar. 27, 2021	33,047,807			6,149,364