Employee Benefit Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 26, 2019
Change in benefit obligation:
Benefit obligation at beginning of period	$ 43,824	$ 35,640
Service cost	1,095	833
Interest cost	1,371	1,485
Actuarial loss	3,806	7,317
Benefits paid	(1,492)	(1,451)
Benefit obligation at end of year	48,604	43,824
Amounts recognized in the statement of financial position consist of:
Current accrued benefit liability (included in Other accrued liabilities)	(1,401)	(1,400)
Noncurrent accrued benefit liability (included in Other long-term obligations)	(47,203)	(42,424)
Total	(48,604)	(43,824)
Amounts recognized in accumulated other comprehensive loss consist of:
Net actuarial loss	19,125	16,373
Prior service credit	(387)	(451)
Total	$ 18,738	$ 15,922