Commitments and Contingent Liabilities - Other (Details) - USD ($)	1 Months Ended			3 Months Ended				12 Months Ended
	Jul. 29, 2016	Dec. 28, 2014	Sep. 29, 2013	Dec. 25, 2016	Sep. 25, 2016	Jun. 26, 2016	Mar. 27, 2016	Dec. 31, 2017	Dec. 25, 2016	Dec. 27, 2015
Loss Contingencies [Line Items]
Multiemployer pension plan withdrawal, reimbursement	$ 5,000,000			$ 0	$ (4,971,000)	$ 11,701,000	$ 0	$ 0	$ 6,730,000	$ 9,055,000
Total amount of letters of credit								56,000,000
Threatened Litigation [Member]
Loss Contingencies [Line Items]
Demand for payment		$ 34,000,000	$ 26,000,000
Decline in contributions, percent			70.00%
Payments made in accordance with ERISA								15,300,000
Expense recognized related to Initial and Revised Assessment								400,000	10,700,000	$ 6,800,000
Partial pension withdrawal arbitration liability								6,500,000
Minimum [Member] | Threatened Litigation [Member]
Loss Contingencies [Line Items]
Partial pension withdrawal contingent loss								0
Maximum [Member] | Threatened Litigation [Member]
Loss Contingencies [Line Items]
Partial pension withdrawal contingent loss								10,000,000
Discontinued Operations [Member]
Loss Contingencies [Line Items]
Litigation settlement charge								700,000	3,700,000
Litigation settlement charge, net of tax								400,000	$ 2,300,000
Letter of Credit [Member]
Loss Contingencies [Line Items]
Securities pledged as collateral								$ 63,100,000