CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Earnings	Noncontrolling Interest	Total
Beginning balance at Dec. 28, 2019	$ 61,409	$ 192,173	$ 995,022	$ (4,889)	$ 14,018	$ 1,257,733
Increase (Decrease) in Stockholders' Equity
Net earnings			40,159		411	40,570
Foreign currency translation adjustment				(5,951)	(2,335)	(8,286)
Unrealized gain (loss) on debt securities				(270)		(270)
Distributions to noncontrolling interest					(299)	(299)
Additional purchases of noncontrolling interest		130			(225)	(95)
Cash dividends			(7,730)			(7,730)
Issuance of shares under employee stock plans	10	309				319
Net issuance of shares under stock grant programs	350	12,454	1			12,805
Issuance of shares under deferred compensation plans	89	(89)
Repurchase of shares	(756)		(28,456)			(29,212)
Expense associated with share-based compensation arrangements		1,404				1,404
Accrued expense under deferred compensation plans		5,343				5,343
Ending balance at Mar. 28, 2020	61,102	211,724	998,996	(11,110)	11,570	1,272,282
Beginning balance at Dec. 28, 2019	61,409	192,173	995,022	(4,889)	14,018	1,257,733
Increase (Decrease) in Stockholders' Equity
Net earnings						110,264
Ending balance at Jun. 27, 2020	61,169	213,809	1,057,817	(8,396)	14,926	1,339,325
Beginning balance at Mar. 28, 2020	61,102	211,724	998,996	(11,110)	11,570	1,272,282
Increase (Decrease) in Stockholders' Equity
Net earnings			66,463		3,231	69,694
Foreign currency translation adjustment				2,026	125	2,151
Unrealized gain (loss) on debt securities				688		688
Cash dividends			(7,644)			(7,644)
Issuance of shares under employee stock plans	10	367				377
Net issuance of shares under stock grant programs	43	(174)	2			(129)
Issuance of shares under deferred compensation plans	14	(14)
Expense associated with share-based compensation arrangements		824				824
Accrued expense under deferred compensation plans		1,082				1,082
Ending balance at Jun. 27, 2020	61,169	213,809	1,057,817	(8,396)	14,926	1,339,325
Beginning balance at Dec. 26, 2020	61,206	218,224	1,182,680	(1,794)	22,836	1,483,152
Increase (Decrease) in Stockholders' Equity
Net earnings			103,311		940	104,251
Foreign currency translation adjustment				(374)	(526)	(900)
Unrealized gain (loss) on debt securities				(1,296)		(1,296)
Distributions to noncontrolling interest					(2,914)	(2,914)
Cash dividends			(9,274)			(9,274)
Issuance of shares under employee stock plans	6	357				363
Net issuance of shares under stock grant programs	537	3,888	5			4,430
Issuance of shares under deferred compensation plans	89	(89)
Expense associated with share-based compensation arrangements		2,936				2,936
Accrued expense under deferred compensation plans		5,795				5,795
Ending balance at Mar. 27, 2021	61,838	231,111	1,276,722	(3,464)	20,336	1,586,543
Beginning balance at Dec. 26, 2020	61,206	218,224	1,182,680	(1,794)	22,836	1,483,152
Increase (Decrease) in Stockholders' Equity
Net earnings						279,611
Ending balance at Jun. 26, 2021	61,851	235,309	1,440,833	(1,464)	23,034	1,759,563
Beginning balance at Mar. 27, 2021	61,838	231,111	1,276,722	(3,464)	20,336	1,586,543
Increase (Decrease) in Stockholders' Equity
Net earnings			173,382		1,978	175,360
Foreign currency translation adjustment				1,759	720	2,479
Unrealized gain (loss) on debt securities				241		241
Cash dividends			(9,276)			(9,276)
Issuance of shares under employee stock plans	9	564				573
Net issuance of shares under stock grant programs	(6)	(224)	5			(225)
Issuance of shares under deferred compensation plans	10	(10)
Expense associated with share-based compensation arrangements		2,728				2,728
Accrued expense under deferred compensation plans		1,140				1,140
Ending balance at Jun. 26, 2021	$ 61,851	$ 235,309	$ 1,440,833	$ (1,464)	$ 23,034	$ 1,759,563