Benefit Plans, Contributions and Benefit Payments, Multiemployer Plan, 401(k) Plans and UMWA Benefit Plans (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) Agreement	Dec. 26, 2015 USD ($)	Dec. 27, 2014 USD ($)
IAM Plan Trusts [Abstract]
Number of collective bargaining agreements | Agreement	2
Pension contributions under the I.A.M. pension plan trusts	$ 1,100	$ 1,100	$ 1,000
Maximum percentage of employer contributions	5.00%
Maximum percentage funded in the red zone, under the Pension Protection act of 2006	65.00%
Maximum percentage funded in the yellow zone, under the Pension Protection act of 2006	80.00%
Minimum percentage funded in the green zone, under the Pension Protection act of 2006	80.00%
401 (k) Plan [Abstract]
Compensation expense for the Company's matching contribution	$ 5,200	4,200	4,100
Contributions to UMWA 1992 Benefit Plan	197	$ 214	$ 249
Pension Benefits [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2017	10,496
2018	10,491
2019	10,496
2020	10,431
2021	10,388
2022-2026	51,211
Total	103,513
Company's expected contribution to benefit plans in next fiscal year	900
Other Benefits [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2017	1,179
2018	1,100
2019	1,052
2020	1,294
2021	1,102
2022-2026	5,902
Total	11,629
Company's expected contribution to benefit plans in next fiscal year	$ 1,200