Segment and Geographic Information - Capital Additions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018
Segment Reporting, Asset Reconciling Item [Line Items]
Capital additions	$ 4,107	$ 3,244
Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Capital additions	3,443	2,935
Operating Segments | TFE
Segment Reporting, Asset Reconciling Item [Line Items]
Capital additions	2,611	1,640
Operating Segments | Photonics
Segment Reporting, Asset Reconciling Item [Line Items]
Capital additions	832	1,295
Unallocated Amount to Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Capital additions	$ 664	$ 309