Leases (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Total finance lease expense	$ 31	$ 6	$ 79	$ 6
Total operating lease expense	594	903	1,870	2,243
Total lease expense	625	909	1,949	2,249
Operating Costs
Total operating lease expense	135	427	506	845
SG&A Expense
Total finance lease expense	26	4	64	4
Total operating lease expense	459	476	1,364	1,398
Interest Expense, Net
Total finance lease expense	$ 5	$ 2	$ 15	$ 2