Segment Information - (Intersegment Sales) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 03, 2021	Jun. 27, 2020	Jul. 03, 2021	Jun. 27, 2020
Segment Reporting Information [Line Items]
Total revenue	$ 75,339	$ 59,146	$ 145,928	$ 126,842
Foil Technology Products
Segment Reporting Information [Line Items]
Total revenue	33,308	31,785	66,019	62,262
Foil Technology Products | Intersegment Eliminations
Segment Reporting Information [Line Items]
Total revenue	959	868	1,920	1,592
Weighing and Control Systems
Segment Reporting Information [Line Items]
Total revenue	24,815	18,445	45,760	40,969
Weighing and Control Systems | Intersegment Eliminations
Segment Reporting Information [Line Items]
Total revenue	$ 150	$ 124	$ 264	$ 211