SIGNIFICANT ACCOUNTING POLICIES - PP&E, Intangibles (Details)	3 Months Ended			9 Months Ended
	Sep. 30, 2018 USD ($)	Jul. 01, 2018 USD ($)	Sep. 24, 2017 USD ($)	Sep. 30, 2018 USD ($) segment company property	Sep. 24, 2017 USD ($)
Property, plant and equipment
Other asset write-downs	$ 14,148,000		$ 8,715,000	$ 14,207,000	$ 10,672,000
Depreciation expense	7,146,000		7,496,000	$ 21,638,000	22,748,000
Assets held for sale
Number of media companies with assets held for sale | company				2
Facilities with reduced carrying value | property				1
Impairment charge of assets held for sale				$ 100,000
Gain (loss) on sale of property		$ 0
Intangible assets:
Goodwill impairment charge	0		0	0	0
Impairment charge of newspaper masthead				14,148,000
Intangible assets subject to amortization, net
Impairment of long-lived assets subject to amortization	0		0	0	0
Financial Obligations
Increase in financing obligations				$ 14,600,000
Segment reporting
Number of operating segments | segment				2
Other asset write-downs
Property, plant and equipment
Write-down of non-newsprint inventory				$ 0	2,000,000
Intangible assets:
Impairment charge of newspaper masthead	$ 14,100,000		$ 8,700,000	$ 14,100,000	$ 8,700,000