Benefit Plans - Contributions and Benefit Payments, Multiemployer Plan, 401(k) Plans and UMWA Benefit Plans (Details) $ in Thousands	12 Months Ended
	Dec. 26, 2020 USD ($) bargain_agreement	Dec. 28, 2019 USD ($)	Dec. 29, 2018 USD ($)
IAM Plan Trusts [Abstract]
Number of collective bargaining agreements | bargain_agreement	2
Multiemployer plan, contributions	$ 1,200	$ 1,200	$ 1,300
Maximum percentage of employer contributions (less than)	5.00%
Multiemployer plans, funded status (as a percent)	80.00%	89.00%
401 (k) Plan [Abstract]
Compensation expense for the Company's matching contribution	$ 5,700	$ 5,400	5,100
Contributions to UMWA 1992 Benefit Plan	$ 57	$ 223	$ 153