CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
		Oct. 02, 2020		Sep. 27, 2019		Oct. 02, 2020		Sep. 27, 2019
Statement Of Income And Comprehensive Income [Abstract]
Consolidated net income		$ 8,258	[1]	$ 8,923	[2]	$ 31,865	[1]	$ 31,556	[2]
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax	[3]	4,302		(2,821)		(1,006)		(3,144)
Pension liability adjustments, net of tax	[4]	(68)		490		769		1,060
Total other comprehensive income (loss)		4,234		(2,331)		(237)		(2,084)
Total consolidated comprehensive income (loss)		$ 12,492		$ 6,592		$ 31,628		$ 29,472

[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.

[3] The tax effect on this component of comprehensive income was nominal for all periods presented.

[4] The tax effect on this component of comprehensive income was nominal for all periods presented. See Note 4 for the total amount of pension liability adjustments reclassified out of accumulated other comprehensive income (loss).