Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
James Horwich [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction	$ 123	$ 251	$ 497	$ 752
Robert E Shaw [Member]
Related Party Transaction [Line Items]
Ownership of Common Stock, Percentage	7.20%		7.20%
Voting Interest of Common Stock, Percentage	3.50%		3.50%
Related Party Transaction, Purchases from Related Party	$ 1,837	$ 2,009	$ 4,870	$ 6,578
Related Party Transaction, Purchases from Related Party, Percentage	2.50%	2.50%	2.20%	2.80%
Robert P Rothman [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction	$ 72	$ 70	$ 212	$ 208