Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]
Balance at Dec. 28, 2018	$ 123,590	$ 57	$ 296,955	$ (136,604)	$ (25,424)	$ (11,394)
Balance, Shares at Dec. 28, 2018		56,615		(27,086)
Issuance of common stock	(2,372)	$ 1	(2,373)
Issuance of common stock, Shares		394
Treasury stock purchased	(1,616)			$ (1,616)
Treasury stock purchased, Shares				(102)
Amortization of restricted stock units and common stock subject to vesting requirements	2,394		2,394
Net income	7,094				7,094
Foreign currency translation	657					657
Balance at Mar. 29, 2019	129,747	$ 58	296,976	$ (138,220)	(18,330)	(10,737)
Ending Balance, Shares at Mar. 29, 2019		57,009		(27,188)
Balance at Dec. 28, 2018	123,590	$ 57	296,955	$ (136,604)	(25,424)	(11,394)
Balance, Shares at Dec. 28, 2018		56,615		(27,086)
Net income	20,992
Foreign currency translation	(1,071)
Balance at Sep. 27, 2019	138,747	$ 58	301,035	$ (139,660)	(10,221)	(12,465)
Ending Balance, Shares at Sep. 27, 2019		57,137		(27,280)
Balance at Mar. 29, 2019	129,747	$ 58	296,976	$ (138,220)	(18,330)	(10,737)
Balance, Shares at Mar. 29, 2019		57,009		(27,188)
Issuance of common stock	405		405
Issuance of common stock, Shares		121
Treasury stock purchased	(1,440)			$ (1,440)
Treasury stock purchased, Shares				(92)
Amortization of restricted stock units and common stock subject to vesting requirements	1,961		1,961
Dividends declared	(5,789)				(5,789)
Net income	6,989				6,989
Foreign currency translation	(672)					(672)
Balance at Jun. 28, 2019	131,201	$ 58	299,342	$ (139,660)	(17,130)	(11,409)
Ending Balance, Shares at Jun. 28, 2019		57,130		(27,280)
Issuance of common stock	(88)		(88)
Issuance of common stock, Shares		7
Amortization of restricted stock units and common stock subject to vesting requirements	1,781		1,781
Net income	6,909				6,909
Foreign currency translation	(1,056)					(1,056)
Balance at Sep. 27, 2019	138,747	$ 58	301,035	$ (139,660)	(10,221)	(12,465)
Ending Balance, Shares at Sep. 27, 2019		57,137		(27,280)
Dividends declared	(5,800)
Balance at Dec. 27, 2019	137,614	$ 58	303,707	$ (141,887)	(13,714)	(10,550)
Ending Balance, Shares at Dec. 27, 2019		57,181		(27,425)
Issuance of common stock	(1,962)		(1,962)
Issuance of common stock, Shares		291
Treasury stock purchased	(1,006)			$ (1,006)
Treasury stock purchased, Shares				(73)
Amortization of restricted stock units and common stock subject to vesting requirements	2,469		2,469
Dividends declared	(13)				(13)
Net income	5,527				5,527
Foreign currency translation	(1,830)					(1,830)
Balance at Mar. 27, 2020	140,799	$ 58	304,214	$ (142,893)	(8,200)	(12,380)
Ending Balance, Shares at Mar. 27, 2020		57,472		(27,498)
Balance at Dec. 27, 2019	137,614	$ 58	303,707	$ (141,887)	(13,714)	(10,550)
Balance, Shares at Dec. 27, 2019		57,181		(27,425)
Net income	4,580
Foreign currency translation	(879)
Balance at Sep. 25, 2020	138,647	$ 58	309,064	$ (143,825)	(15,221)	(11,429)
Ending Balance, Shares at Sep. 25, 2020		57,560		(27,573)
Balance at Mar. 27, 2020	140,799	$ 58	304,214	$ (142,893)	(8,200)	(12,380)
Balance, Shares at Mar. 27, 2020		57,472		(27,498)
Issuance of common stock	359		359
Issuance of common stock, Shares		75
Amortization of restricted stock units and common stock subject to vesting requirements	2,362		2,362
Dividends declared	(3,050)				(3,050)
Net income	(3,933)				(3,933)
Foreign currency translation	44					44
Balance at Jun. 26, 2020	136,581	$ 58	306,935	$ (142,893)	(15,183)	(12,336)
Ending Balance, Shares at Jun. 26, 2020		57,547		(27,498)
Issuance of common stock	(1,041)		(109)	$ (932)
Issuance of common stock, Shares		13		(75)
Amortization of restricted stock units and common stock subject to vesting requirements	2,238		2,238
Dividends declared	(3,024)				(3,024)
Net income	2,986				2,986
Foreign currency translation	907					907
Balance at Sep. 25, 2020	$ 138,647	$ 58	$ 309,064	$ (143,825)	$ (15,221)	$ (11,429)
Ending Balance, Shares at Sep. 25, 2020		57,560		(27,573)