Contingent Liabilities - Other (Details) - USD ($)	1 Months Ended			3 Months Ended
	Jul. 29, 2016	Dec. 31, 2014	Sep. 30, 2013	Mar. 26, 2017	Dec. 25, 2016	Mar. 27, 2016
Loss Contingencies [Line Items]
Amount paid related to Revised Assessment	$ 5,000,000
Threatened Litigation
Loss Contingencies [Line Items]
Demand for payment		$ 34,000,000	$ 26,000,000
Decline in contributions, percent (more than)			70.00%
Payments related to Initial Assessment				$ 12,600,000
Amount recognized as expense in the period				100,000		$ 1,800,000
Partial pension withdrawal arbitration liability				8,900,000
Minimum | Threatened Litigation
Loss Contingencies [Line Items]
Estimate of possible loss				0
Maximum | Threatened Litigation
Loss Contingencies [Line Items]
Estimate of possible loss				$ 10,000,000
New England Media Group [Member]
Loss Contingencies [Line Items]
Charge recorded within discontinued operations					$ 3,700,000