Schedule II - Valuation and Qualifying Accounts (Details) - Allowance for Doubtful Accounts - USD ($) $ in Thousands	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 699	$ 714	$ 884
Additions charged to costs and expenses	1,391	815	915
Deductions from reserves	(1,192)	(830)	(1,085)
Balance at end of period	$ 898	$ 699	$ 714