Computation of Basic and Diluted Earnings per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jul. 03, 2020	[1]	Jun. 28, 2019	[2]	Jul. 03, 2020	[1]	Jun. 28, 2019	[2]
Numerators:
Consolidated net income	$ 11,660		$ 10,380		$ 23,607		$ 22,633
Denominators:
Weighted average common shares outstanding—basic	35,137		34,998		35,145		34,981
Dilutive potential common shares	442		505		425		510
Weighted average common shares outstanding— diluted	35,579		35,503		35,570		35,491
Antidilutive potential common shares excluded from above			36		26		47
Earnings per Common Share:
Basic	$ 0.33		$ 0.30		$ 0.67		$ 0.65
Diluted	$ 0.33		$ 0.29		$ 0.66		$ 0.64

[1] 71 thousand non-GAAP EPS performance-based restricted stock units granted to certain members of the executive management team and 213 thousand shares of restricted stock issued to the former Laser Quantum non-controlling interest shareholders are considered contingently issuable shares and were excluded from the calculation of the denominator as the contingent conditions had not been met as of July 3, 2020.

[2] 45 thousand non-GAAP EPS performance-based restricted stock units granted to certain members of the executive management team and 213 thousand shares of restricted stock issued to the former Laser Quantum non-controlling interest shareholders were considered contingently issuable shares and were excluded from the calculation of the denominator as the contingent conditions had not been met as of June 28, 2019.