Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Equity Offering [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]	Previously Reported [Member]	Common Stock [Member]	Common Stock [Member] Equity Offering [Member]	Common Stock [Member] Previously Reported [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Equity Offering [Member]	Additional Paid-in Capital [Member] Previously Reported [Member]	Accumulated Other Comprehensive Loss [Member]	Retained Earnings (Accumulated Deficit) [Member]	Retained Earnings (Accumulated Deficit) [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Retained Earnings (Accumulated Deficit) [Member] Previously Reported [Member]	Treasury Stock [Member]	Treasury Stock [Member] Previously Reported [Member]
Beginning Balance at Dec. 30, 2017			$ 1,883	$ 175,325			$ 525			$ 252,275			$ 1,883	$ (64,716)		$ (12,759)
Begining Balance, Shares at Dec. 30, 2017							49,805,338
Beginning Balance at Dec. 30, 2017	$ 177,208				$ 525			$ 252,275				$ (62,833)			$ (12,759)
Beginning Balance, Shares at Dec. 30, 2017					49,805,338
Beginning Balance at Dec. 30, 2017			$ 1,883	$ 175,325			$ 525			$ 252,275			$ 1,883	$ (64,716)		$ (12,759)
Begining Balance, Shares at Dec. 30, 2017							49,805,338
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201409Member
Beginning Balance at Dec. 30, 2017	$ 177,208				$ 525			252,275				(62,833)			(12,759)
Beginning Balance, Shares at Dec. 30, 2017					49,805,338
Grants of restricted stock					$ 2			(2)
Vesting of restricted stock, Shares					162,841
Forfeitures of restricted stock					$ (1)			1
Purchases of treasury stock	(687)														(687)
Purchases of treasury stock, Shares					(35,691)
Retirement of treasury stock								(687)							687
Stock-based compensation	2,796							2,796
Exercise of stock options	$ 2,239				$ 11			2,228
Exercise of stock options, Shares	1,119,247				1,119,247
Common stock issued under equity offering		$ 152,503				$ 70			$ 152,433
Common stock issued under equity offering, Shares						7,000,000
Common stock issued in employee grant	$ 587							587
Common stock issued in employee grant, Shares	28,160				28,160
Common stock issued under ESPP	$ 30							30
Common stock issued under ESPP, Shares					1,645
Other comprehensive income (loss)	(3,065)										$ (3,065)
Net income	53,933											53,933
Ending Balance at Dec. 29, 2018	385,544				$ 607			409,661			(3,065)	(8,900)			(12,759)
Ending Balance, Shares at Dec. 29, 2018					58,081,540
Grants of restricted stock					$ 6			(6)
Vesting of restricted stock, Shares					164,226
Forfeitures of restricted stock					$ (1)			1
Purchases of treasury stock	(6,055)														(6,055)
Purchases of treasury stock, Shares					(428,059)
Retirement of treasury stock								(505)							505
Stock-based compensation	3,923							3,923
Exercise of stock options	$ 1,562				$ 7			1,555
Exercise of stock options, Shares	682,931				682,931
Common stock issued under ESPP	$ 59							59
Common stock issued under ESPP, Shares					4,096
Other comprehensive income (loss)	2,827										2,827
Net income	43,688											43,688
Ending Balance at Dec. 28, 2019	431,548				$ 619			414,688			(238)	34,788			(18,309)
Ending Balance, Shares at Dec. 28, 2019					58,504,734
Grants of restricted stock					$ 7			(7)
Vesting of restricted stock, Shares					219,977
Forfeitures of restricted stock					$ (3)			3
Purchases of treasury stock	(815)														(815)
Purchases of treasury stock, Shares					(51,479)
Retirement of treasury stock					$ (1)			(814)							815
Stock-based compensation	5,458							5,458
Exercise of stock options	$ 572				$ 3			569
Exercise of stock options, Shares	284,353				284,353
Common stock issued under ESPP	$ 305							305
Common stock issued under ESPP, Shares					41,126
Other comprehensive income (loss)	2,958										2,958
Net income	45,108											45,108
Ending Balance at Jan. 02, 2021	$ 485,134				$ 625			$ 420,202			$ 2,720	$ 79,896			$ (18,309)
Ending Balance, Shares at Jan. 02, 2021					58,998,711