Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock Issued	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Balance (in shares) at Dec. 31, 2017		11,121
Balance at Dec. 31, 2017	$ 183,372	$ 111	$ 67,526	$ 117,415	$ (1,680)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	6,111			6,111
Foreign currency translation adjustments	487				487
Unrealized gain on cash flow hedge	403				403
Employee stock awards and stock options (in shares)		101
Employee stock awards and stock options	523	$ 1	522
Stock-based compensation	867		867
Balance (in shares) at Mar. 30, 2018		11,222
Balance at Mar. 30, 2018	191,686	$ 112	68,915	123,449	(790)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effects of adoption of Accounting Standards Update	0
Balance (in shares) at Dec. 31, 2018		11,267
Balance at Dec. 31, 2018	221,300	$ 113	71,729	152,616	(3,158)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	7,091			7,091
Foreign currency translation adjustments	(823)				(823)
Unrealized gain on cash flow hedge	(360)				(360)
Employee stock awards and stock options (in shares)		85
Employee stock awards and stock options	(81)	$ 1	(82)
Stock-based compensation	1,117		1,117
Balance (in shares) at Mar. 29, 2019		11,352
Balance at Mar. 29, 2019	228,244	$ 114	$ 72,764	$ 159,966	$ (4,600)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effects of adoption of Accounting Standards Update	$ (259)