Computation of Basic and Diluted Earnings per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				9 Months Ended
	Oct. 02, 2020	[1]	Sep. 27, 2019	[2]	Oct. 02, 2020	[1]	Sep. 27, 2019	[2]
Numerators:
Consolidated net income	$ 8,258		$ 8,923		$ 31,865		$ 31,556
Denominators:
Weighted average common shares outstanding—basic	35,142		35,074		35,144		35,012
Dilutive potential common shares	546		511		465		511
Weighted average common shares outstanding— diluted	35,688		35,585		35,609		35,523
Antidilutive potential common shares excluded from above			35		17		43
Earnings per Common Share:
Basic	$ 0.23		$ 0.25		$ 0.91		$ 0.90
Diluted	$ 0.23		$ 0.25		$ 0.89		$ 0.89

[1] 73 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 October 2, 2020.

[2] 47 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 September 27, 2019.