Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Dec. 28, 2018	$ 751,873	$ 165,171	$ 510,825	$ 220,734	$ (144,857)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued	34,974	1,747	33,227	0	0
Stock Repurchased During Period, Value	2,683	60	186	2,437	0
Stock compensation cost	19,700	0	19,700	0	0
Net Earnings	259,018	0	0	259,018	0
Dividends, Common Stock, Cash	(79,998)	0	0	(79,998)	0
Other comprehensive income (loss)	912	0	0	0	912
Ending Balance at Sep. 27, 2019	983,796	166,858	563,566	397,317	(143,945)
Beginning Balance at Jun. 28, 2019	925,958	166,792	556,170	342,308	(139,312)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued	2,289	126	2,163	0	0
Stock Repurchased During Period, Value	2,683	60	186	2,437	0
Stock compensation cost	5,419	0	5,419	0	0
Net Earnings	84,132	0	0	84,132	0
Dividends, Common Stock, Cash	(26,686)	0	0	(26,686)	0
Other comprehensive income (loss)	(4,633)	0	0	0	(4,633)
Ending Balance at Sep. 27, 2019	983,796	166,858	563,566	397,317	(143,945)
Beginning Balance at Dec. 27, 2019	1,024,931	167,287	578,440	448,991	(169,787)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued	56,883	2,484	54,399	0	0
Stock Repurchased During Period, Value	102,143	2,327	8,047	91,769	0
Stock compensation cost	19,407	0	19,407	0	0
Net Earnings	215,765	0	0	215,765	0
Dividends, Common Stock, Cash	(87,778)	0	0	(87,778)	0
Other comprehensive income (loss)	38,872	0	0	0	38,872
Ending Balance at Sep. 25, 2020	1,165,937	167,444	644,199	485,209	(130,915)
Beginning Balance at Jun. 26, 2020	1,026,968	166,693	623,803	400,154	(163,682)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued	15,732	751	14,981	0	0
Stock Repurchased During Period, Value	0	0	0	0	0
Stock compensation cost	5,415	0	5,415	0	0
Net Earnings	114,115	0	0	114,115	0
Dividends, Common Stock, Cash	(29,060)	0	0	(29,060)	0
Other comprehensive income (loss)	32,767	0	0	0	32,767
Ending Balance at Sep. 25, 2020	$ 1,165,937	$ 167,444	$ 644,199	$ 485,209	$ (130,915)