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. 26, 2015	$ 20,142	$ 171,562	$ 565,636	$ (4,585)	$ 13,654	$ 766,409
Increase (Decrease) in Stockholders' Equity
Net earnings			52,611		1,882	54,493
Foreign currency translation adjustment				250	(801)	(551)
Unrealized gain (loss) on investment & foreign currency				186		186
Distributions to noncontrolling interest					(1,731)	(1,731)
Additional purchases of noncontrolling interest		855			(1,955)	(1,100)
Cash dividends $0.450 and $0.42 per share (periods ending July 1, 2017 and June 25, 2016, respectively)			(8,529)			(8,529)
Issuance of 4,233 and 3,708 shares under employee stock plans (periods ending July 1, 2017 and June 25, 2016, respectively)	3	287				290
Issuance of 142,145 and 114,132 shares under stock grant programs (periods ending July 1, 2017 and June 25, 2016, respectively)	114	5,134				5,248
Issuance of 44,208 and 47,914 shares under deferred compensation plans (periods ending July 1, 2017 and June 25, 2016, respectively)	48	(48)
Expense associated with share-based compensation arrangements		977				977
Accrued expense under deferred compensation plans		3,943				3,943
Ending balance at Jun. 25, 2016	20,307	182,710	609,718	(4,149)	11,049	819,635
Beginning balance at Dec. 31, 2016	20,342	185,333	649,135	(5,630)	11,286	860,466
Increase (Decrease) in Stockholders' Equity
Net earnings			54,704		1,505	56,209
Foreign currency translation adjustment				2,817	1,382	4,199
Unrealized gain (loss) on investment & foreign currency				223		223
Distributions to noncontrolling interest					(1,953)	(1,953)
Additional purchases of noncontrolling interest					2,409	2,409
Cash dividends $0.450 and $0.42 per share (periods ending July 1, 2017 and June 25, 2016, respectively)			(9,208)			(9,208)
Issuance of 4,233 and 3,708 shares under employee stock plans (periods ending July 1, 2017 and June 25, 2016, respectively)	5	327				332
Issuance of 142,145 and 114,132 shares under stock grant programs (periods ending July 1, 2017 and June 25, 2016, respectively)	142	7,068				7,210
Issuance of 44,208 and 47,914 shares under deferred compensation plans (periods ending July 1, 2017 and June 25, 2016, respectively)	44	(44)
Repurchase of 110,880 shares	(111)		(9,823)			(9,934)
Expense associated with share-based compensation arrangements		1,282				1,282
Accrued expense under deferred compensation plans		5,126				5,126
Ending balance at Jul. 01, 2017	$ 20,422	$ 199,092	$ 684,808	$ (2,590)	$ 14,629	$ 916,361