Revenue (Contract Balances) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 26, 2022	Mar. 27, 2021
Contract With Customer, Change In Liability [Roll Forward]
Beginning contract liability	$ 1,285	$ 1,005
Revenue recognized from contract liabilities included in the beginning balance	(908)	(927)
Increases due to cash received, net of amounts recognized in revenue during the period	921	1,131
Ending contract liability	$ 1,298	$ 1,209
Product warranty period	2 years