Commitments and Contingent Liabilities - Other (Details) - USD ($)	1 Months Ended			12 Months Ended
	Jul. 29, 2016	Dec. 28, 2014	Sep. 29, 2013	Dec. 30, 2018	Dec. 31, 2017	Dec. 25, 2016
Loss Contingencies [Line Items]
Multiemployer pension plan withdrawal, reimbursement	$ 5,000,000					$ 6,700,000
Total amount of letters of credit				$ 48,800,000	$ 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				18,900,000
Expense recognized related to Initial and Revised Assessment				300,000	400,000	10,700,000
Partial pension withdrawal arbitration liability				3,200,000
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				11,000,000
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				$ 54,200,000	$ 63,000,000