CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]
Balance, value at Dec. 30, 2017	$ 721,950	$ 497,093	$ (15,136)	$ 239,993
Balance, shares at Dec. 30, 2017		36,466
Net earnings	12,343			12,343
Other comprehensive income	84		84
Dividends	(6,526)			(6,526)
Share repurchases, value	(20,000)	$ (20,000)
Share repurchases, shares		(952)
Stock-based employee compensation	5,290	$ 5,290
Issuances of common stock on stock option exercises and for stock bonus plan and associate stock purchase plan, value	470	$ 470
Issuances of common stock on stock option exercises and for stock bonus plan and associate stock purchase plan, shares		24
Issuances of restricted stock, shares		472
Cancellations of stock-based awards, value	(1,567)	$ (1,567)
Cancellations of stock-based awards, shares		(87)
Balance, value at Apr. 21, 2018	712,044	$ 481,286	(15,052)	245,810
Balance, shares at Apr. 21, 2018		35,923
Balance, value at Dec. 29, 2018	$ 715,947	$ 484,064	(15,759)	247,642
Balance, shares at Dec. 29, 2018	35,952	35,952
Impact of adoption of new lease standard (ASU 2016-02) \| (ASU 2016-02) [Member]	$ (26,863)			(26,863)
Net earnings	7,469			7,469
Other comprehensive income	60		60
Dividends	(6,902)			(6,902)
Stock-based employee compensation	5,383	$ 5,383
Issuances of common stock on stock option exercises and for stock bonus plan and associate stock purchase plan, value	452	$ 452
Issuances of common stock on stock option exercises and for stock bonus plan and associate stock purchase plan, shares		30
Issuances of restricted stock, shares		444
Cancellations of stock-based awards, value	(1,744)	$ (1,744)
Cancellations of stock-based awards, shares		(107)
Balance, value at Apr. 20, 2019	$ 693,802	$ 488,155	$ (15,699)	$ 221,346
Balance, shares at Apr. 20, 2019	36,319	36,319

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