CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid in Capital	Accumulated Other Comprehensive Loss	Retained Earnings
Balance (in shares) at Dec. 30, 2016		26,280,469
Balance at Dec. 30, 2016	$ 193,760	$ 263	$ 127,180	$ (2,186)	$ 68,503
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	(1,642)				(1,642)
Stock compensation (in shares)		106,558
Stock compensation	743	$ 1	742
Cumulative translation adjustment	1			1
Shares surrendered to pay withholding taxes (in shares)		(16,155)
Shares surrendered to pay withholding taxes	(239)		(239)
Balance (in shares) at Mar. 31, 2017		26,370,872
Balance at Mar. 31, 2017	192,623	$ 264	127,683	(2,185)	66,861
Balance (in shares) at Dec. 30, 2016		26,280,469
Balance at Dec. 30, 2016	193,760	$ 263	127,180	(2,186)	68,503
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,883
Cumulative translation adjustment	605
Balance (in shares) at Sep. 29, 2017		26,564,168
Balance at Sep. 29, 2017	204,476	$ 266	132,405	(1,581)	73,386
Balance (in shares) at Mar. 31, 2017		26,370,872
Balance at Mar. 31, 2017	192,623	$ 264	127,683	(2,185)	66,861
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,674				3,674
Stock compensation (in shares)		2,863
Stock compensation	869		869
Cumulative translation adjustment	235			235
Shares surrendered to pay withholding taxes (in shares)		(5,800)
Shares surrendered to pay withholding taxes	(79)		(79)
Balance (in shares) at Jun. 30, 2017		26,367,935
Balance at Jun. 30, 2017	197,322	$ 264	128,473	(1,950)	70,535
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,851				2,851
Stock compensation (in shares)		20,579
Stock compensation	770		770
Shares issued for Fells Point acquisition (in shares)		185,442
Shares issued for Fells Point acquisition	3,300	$ 2	3,298
Cumulative translation adjustment	369			369
Shares surrendered to pay withholding taxes (in shares)		(9,788)
Shares surrendered to pay withholding taxes	(136)		(136)
Balance (in shares) at Sep. 29, 2017		26,564,168
Balance at Sep. 29, 2017	$ 204,476	$ 266	132,405	(1,581)	73,386
Balance (in shares) at Dec. 29, 2017	28,442,208	28,442,208
Balance at Dec. 29, 2017	$ 248,601	$ 284	166,997	(1,549)	82,869
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	544				544
Stock compensation (in shares)		284,618
Stock compensation	837	$ 3	834
Cumulative translation adjustment	(922)			(922)
Shares surrendered to pay withholding taxes (in shares)		(20,100)
Shares surrendered to pay withholding taxes	(472)		(472)
Balance (in shares) at Mar. 30, 2018		28,706,726
Balance at Mar. 30, 2018	$ 248,588	$ 287	167,359	(2,471)	83,413
Balance (in shares) at Dec. 29, 2017	28,442,208	28,442,208
Balance at Dec. 29, 2017	$ 248,601	$ 284	166,997	(1,549)	82,869
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	11,520
Cumulative translation adjustment	$ (1,299)
Balance (in shares) at Sep. 28, 2018	19,970,198	29,970,198
Balance at Sep. 28, 2018	$ 298,145	$ 300	206,304	(2,848)	94,389
Balance (in shares) at Mar. 30, 2018		28,706,726
Balance at Mar. 30, 2018	248,588	$ 287	167,359	(2,471)	83,413
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	6,819				6,819
Stock compensation (in shares)		23,547
Stock compensation	1,072		1,072
Cumulative translation adjustment	(281)			(281)
Shares surrendered to pay withholding taxes (in shares)		(4,200)
Shares surrendered to pay withholding taxes	(99)		(99)
Balance (in shares) at Jun. 29, 2018		28,726,073
Balance at Jun. 29, 2018	256,099	$ 287	168,332	(2,752)	90,232
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,157				4,157
Stock compensation (in shares)		2,000
Stock compensation	1,090		1,090
Conversion of subordinated notes (in shares)		1,246,272
Conversion of subordinated notes	37,015	$ 13	37,002
Cumulative translation adjustment	(96)			(96)
Shares surrendered to pay withholding taxes (in shares)		(4,147)
Shares surrendered to pay withholding taxes	$ (120)		(120)
Balance (in shares) at Sep. 28, 2018	19,970,198	29,970,198
Balance at Sep. 28, 2018	$ 298,145	$ 300	$ 206,304	$ (2,848)	$ 94,389