Related Party Transactions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
James Horwich [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction	$ 1,003	$ 978	$ 793
Robert E Shaw [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction	$ 8,200	$ 7,200	$ 7,300
Ownership of Common Stock, Percentage	7.20%
Voting Interest of Common Stock, Percentage	3.50%
Related Party Transaction, Purchases from Related Party, Percentage	2.60%	2.30%	2.40%
Robert P Rothman [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction	$ 278	$ 273	$ 267