CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]
Balance, value at Dec. 28, 2013	$ 706,873	$ 518,056	$ (8,794)	$ 197,611
Balance, shares at Dec. 28, 2013		37,371
Net earnings	58,596			58,596
Other comprehensive income (loss)	(2,861)		(2,861)
Dividends	(18,090)			(18,090)
Share repurchase, value	(4,987)	$ (4,987)
Share repurchase, shares		(246)
Stock-based employee compensation	6,939	$ 6,939
Issuance of common stock and related tax benefit on stock option exercises and stock bonus plan and from deferred compensation plan, value	1,824	$ 1,824
Issuance of common stock and related tax benefit on stock option exercises and stock bonus plan and from deferred compensation plan, shares		173
Issuance of restricted stock and related income tax benefits, value	588	$ 588
Issuance of restricted stock and related income tax benefits, shares		317
Cancellations of stock-based awards, value	(1,629)	$ (1,629)
Cancellations of stock-based awards, shares		(91)
Balance, value at Jan. 03, 2015	747,253	$ 520,791	(11,655)	238,117
Balance, shares at Jan. 03, 2015		37,524
Net earnings	62,710			62,710
Other comprehensive income (loss)	208		208
Dividends	(20,299)			(20,299)
Share repurchase, value	(9,000)	$ (9,000)
Share repurchase, shares		(282)
Stock-based employee compensation	7,240	$ 7,240
Issuance of common stock and related tax benefit on stock option exercises and stock bonus plan and from deferred compensation plan, value	4,279	$ 4,279
Issuance of common stock and related tax benefit on stock option exercises and stock bonus plan and from deferred compensation plan, shares		223
Issuance of restricted stock and related income tax benefits, value	1,114	$ 1,114
Issuance of restricted stock and related income tax benefits, shares		315
Cancellations of stock-based awards, value	(2,726)	$ (2,726)
Cancellations of stock-based awards, shares		(180)
Balance, value at Jan. 02, 2016	$ 790,779	$ 521,698	(11,447)	280,528
Balance, shares at Jan. 02, 2016	37,600	37,600
Net earnings	$ 56,828			56,828
Other comprehensive income (loss)	10		10
Dividends	(22,496)			(22,496)
Share repurchase, value	(9,000)	$ (9,000)
Share repurchase, shares		(396)
Stock-based employee compensation	7,936	$ 7,936
Issuance of common stock and related tax benefit on stock option exercises and stock bonus plan and from deferred compensation plan, value	3,697	$ 3,697
Issuance of common stock and related tax benefit on stock option exercises and stock bonus plan and from deferred compensation plan, shares		144
Issuance of restricted stock and related income tax benefits, value	(118)	$ (118)
Issuance of restricted stock and related income tax benefits, shares		315
Cancellations of stock-based awards, value	(2,229)	$ (2,229)
Cancellations of stock-based awards, shares		(124)
Balance, value at Dec. 31, 2016	$ 825,407	$ 521,984	$ (11,437)	$ 314,860
Balance, shares at Dec. 31, 2016	37,539	37,539