Asset impairment and facility consolidation charges (gains) (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 28, 2014
Unusual or Infrequent Item [Line Items]
Goodwill impairment charges			$ 15,218	$ 8,000	$ 30,300
Total asset impairment and facility consolidation charges (gains) against operations			32,130	(58,857)	44,961
Asset impairment charges			4,700
Digital
Unusual or Infrequent Item [Line Items]
Goodwill impairment charges	$ 15,200		15,218	8,000
Media
Unusual or Infrequent Item [Line Items]
Goodwill impairment charges			0	0
Operating Segments | Digital
Unusual or Infrequent Item [Line Items]
Goodwill impairment charges	$ 15,200		15,218	8,000	30,271
Impairment of other intangibles				900	971
Other impairment charges			5,915	13,095
Asset impairment charges			1,400
Lease exit costs			4,600
Operating Segments | Media
Unusual or Infrequent Item [Line Items]
Other impairment charges			8,633	8,078	13,719
Corporate
Unusual or Infrequent Item [Line Items]
Other impairment charges			2,364	962
Segment Reconciling Items
Unusual or Infrequent Item [Line Items]
Gain on sale of corporate headquarters		$ (89,900)	0	$ (89,892)	$ 0
Gain on sale of corporate headquarters, net of tax		$ 54,900
Internally produced program | Operating Segments | Media
Unusual or Infrequent Item [Line Items]
Asset impairment charges			$ 6,200