CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Accumulated Other Comprehensive Loss [Member]	Retained Earnings [Member]
Balance, value at Dec. 29, 2018	$ 715,947	$ 484,064	$ (15,759)	$ 247,642
Balance, shares at Dec. 29, 2018		35,952
Impact of adoption of new standard | (ASU 2016-02) [Member]	(26,863)			(26,863)
Net earnings (loss)	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	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
Balance, value at Dec. 29, 2018	715,947	$ 484,064	(15,759)	247,642
Balance, shares at Dec. 29, 2018		35,952
Net earnings (loss)	655
Other comprehensive income	6,827
Balance, value at Jul. 13, 2019	687,645	$ 488,947	(8,932)	207,630
Balance, shares at Jul. 13, 2019		36,334
Balance, value at Apr. 20, 2019	693,802	$ 488,155	(15,699)	221,346
Balance, shares at Apr. 20, 2019		36,319
Net earnings (loss)	(6,814)			(6,814)
Other comprehensive income	6,767		6,767
Dividends	(6,902)			(6,902)
Stock-based employee compensation	715	$ 715
Issuances of common stock on stock option exercises and for stock bonus plan and associate stock purchase plan	99	$ 99
Issuances of common stock on stock option exercises and for stock bonus plan and associate stock purchase plan, shares		8
Issuances of restricted stock, shares		22
Cancellations of stock-based awards, value	(22)	$ (22)
Cancellations of stock-based awards, shares		(15)
Balance, value at Jul. 13, 2019	687,645	$ 488,947	(8,932)	207,630
Balance, shares at Jul. 13, 2019		36,334
Balance, value at Dec. 28, 2019	$ 687,538	$ 490,233	(1,600)	198,905
Balance, shares at Dec. 28, 2019	36,351	36,351
Impact of adoption of new standard | (ASU 2016-13) [Member]	$ (1,612)			(1,612)
Net earnings (loss)	15,402			15,402
Other comprehensive income	80		80
Dividends	(6,997)			(6,997)
Share repurchase, value	(10,000)	$ (10,000)
Share repurchase, shares		(861)
Stock-based employee compensation	2,342	$ 2,342
Issuances of common stock on stock option exercises and for stock bonus plan and associate stock purchase plan	291	$ 291
Issuances of common stock on stock option exercises and for stock bonus plan and associate stock purchase plan, shares		21
Issuances of restricted stock, shares		293
Cancellations of stock-based awards, value	(1,352)	$ (1,352)
Cancellations of stock-based awards, shares		(122)
Balance, value at Apr. 18, 2020	685,692	$ 481,514	(1,520)	205,698
Balance, shares at Apr. 18, 2020		35,682
Balance, value at Dec. 28, 2019	$ 687,538	$ 490,233	(1,600)	198,905
Balance, shares at Dec. 28, 2019	36,351	36,351
Net earnings (loss)	$ 43,869
Other comprehensive income	100
Balance, value at Jul. 11, 2020	$ 709,251	$ 483,484	(1,500)	227,267
Balance, shares at Jul. 11, 2020	35,842	35,842
Balance, value at Apr. 18, 2020	$ 685,692	$ 481,514	(1,520)	205,698
Balance, shares at Apr. 18, 2020		35,682
Net earnings (loss)	28,467			28,467
Other comprehensive income	20		20
Dividends	(6,898)			(6,898)
Stock-based employee compensation	1,904	$ 1,904
Issuances of common stock on stock option exercises and for stock bonus plan and associate stock purchase plan	100	$ 100
Issuances of common stock on stock option exercises and for stock bonus plan and associate stock purchase plan, shares		6
Issuances of restricted stock, shares		159
Cancellations of stock-based awards, value	(34)	$ (34)
Cancellations of stock-based awards, shares		(5)
Balance, value at Jul. 11, 2020	$ 709,251	$ 483,484	$ (1,500)	$ 227,267
Balance, shares at Jul. 11, 2020	35,842	35,842