Business Segments - Revenue Information by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 03, 2021	Jun. 27, 2020	Jul. 03, 2021	Jun. 27, 2020
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 13,426	$ 6,219	$ 25,385	$ 15,240
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	6,508	3,171	12,072	7,612
Asia/Pacific Rim
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	3,280	1,410	6,454	3,603
Europe
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	3,243	1,419	5,660	3,403
Rest of Americas
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 395	$ 219	$ 1,199	$ 622