Schedule II - Valuation and Qualifying Accounts - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 26, 2020	Dec. 28, 2019	Dec. 29, 2018
SEC Schedule, 12-09, Allowance, Credit Loss [Member]
Balance, beginning of year		$ 9	$ 40	$ 200
Additions (reductions) not charged to expense	[1]	(1)	24	(20)
Additions (reduction) charged (credited) to expense		79	(28)	(109)
Deductions/write-offs		(41)	27	31
Balance, end of year		128	9	40
SEC Schedule, 12-09, Reserve, Inventory [Member]
Balance, beginning of year		20,958	23,938	17,362
Additions (reductions) not charged to expense	[1]	4,611	1,285	(300)
Additions (reduction) charged (credited) to expense		8,117	4,792	10,783
Balance, end of year		26,937	20,958	23,938
Deductions/write-offs		$ 6,749	$ 9,057	$ 3,907

[1] Changes in reserve balances resulting from foreign currency impact and reclassifications from other reserves.