Summary of Restructuring Charges by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Restructuring Cost And Reserve [Line Items]
Restructuring costs	$ 1,165	$ 698	$ 2,711	$ 1,353
2020 Restructuring
Restructuring Cost And Reserve [Line Items]
Restructuring costs	1,165		2,503
2020 Restructuring | Photonics
Restructuring Cost And Reserve [Line Items]
Restructuring costs	195		490
2020 Restructuring | Vision
Restructuring Cost And Reserve [Line Items]
Restructuring costs	275		697
2020 Restructuring | Precision Motion
Restructuring Cost And Reserve [Line Items]
Restructuring costs	$ 695		$ 1,316