Business Segments - Schedule of Revenue Information by Product (Parenthetical) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Entity Wide Information Revenue From External Customer [Line Items]
Total revenues	$ 6,219	$ 10,426	$ 15,240	$ 21,021
Service Contract Revenues
Entity Wide Information Revenue From External Customer [Line Items]
Total revenues	$ 311	$ 296	$ 627	$ 604