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	32,685	1,621	31,064	0	0
Stock compensation cost	14,281	0	14,281	0	0
Net Earnings	174,886	0	0	174,886	0
Dividends declared	(53,312)	0	0	(53,312)	0
Other comprehensive income (loss)	5,545	0	0	0	5,545
Ending Balance at Jun. 28, 2019	925,958	166,792	556,170	342,308	(139,312)
Beginning Balance at Mar. 29, 2019	844,438	166,364	539,067	281,038	(142,031)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued	9,106	428	8,678	0	0
Stock compensation cost	8,425	0	8,425	0	0
Net Earnings	88,137	0	0	88,137	0
Dividends declared	(26,867)	0	0	(26,867)	0
Other comprehensive income (loss)	2,719	0	0	0	2,719
Ending Balance at Jun. 28, 2019	925,958	166,792	556,170	342,308	(139,312)
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	41,151	1,733	39,418	0	0
Shares repurchased	(102,143)	(2,327)	(8,047)	(91,769)	0
Stock compensation cost	13,992	0	13,992	0	0
Net Earnings	101,650	0	0	101,650	0
Dividends declared	(58,718)	0	0	(58,718)	0
Other comprehensive income (loss)	6,105	0	0	0	6,105
Ending Balance at Jun. 26, 2020	1,026,968	166,693	623,803	400,154	(163,682)
Beginning Balance at Mar. 27, 2020	1,018,658	166,840	612,698	411,450	(172,330)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued	4,064	113	3,951	0	0
Shares repurchased	(12,114)	(260)	(904)	(10,950)	0
Stock compensation cost	8,058	0	8,058	0	0
Net Earnings	28,832	0	0	28,832	0
Dividends declared	(29,178)	0	0	(29,178)	0
Other comprehensive income (loss)	8,648	0	0	0	8,648
Ending Balance at Jun. 26, 2020	$ 1,026,968	$ 166,693	$ 623,803	$ 400,154	$ (163,682)