Business Segments - Revenue Information by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 02, 2021	Sep. 26, 2020	Oct. 02, 2021	Sep. 26, 2020
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 13,264	$ 8,803	$ 38,649	$ 24,043
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	6,901	5,269	18,973	12,881
Asia/Pacific Rim
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	2,825	1,022	9,279	4,625
Europe
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	3,025	1,913	8,685	5,316
Rest of Americas
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 513	$ 599	$ 1,712	$ 1,221