Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2021	Dec. 26, 2020
Allowance for doubtful accounts
Year ended:
Balance at beginning of year	$ 92	$ 161
Charged to costs and expenses	46	39
Charged to other accounts	0	0
Deductions	30	108
Balance at end of year	108	92
Provision for claims, allowances and warranties
Year ended:
Balance at beginning of year	3,504	3,402
Charged to costs and expenses	6,027	5,732
Charged to other accounts	0	0
Deductions	5,820	5,630
Balance at end of year	$ 3,711	$ 3,504