Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 29,785	$ 19,747	$ 29,958	$ 19,254
Components of other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(732)	(698)	1,239	(1,207)
Amortization of defined benefit pension items:
Net actuarial loss (gain)	17	(1,498)	33	(1,466)
Prior service cost	11	12	23	24
Defined benefit pension plan adjustments	28	(1,486)	56	(1,442)
Other comprehensive income (loss), net of tax	760	(788)	(1,183)	(235)
Comprehensive income	$ 30,545	$ 18,959	$ 28,775	$ 19,019

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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