Investments - Madison (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 24, 2017	Sep. 25, 2016	Sep. 24, 2017	Sep. 25, 2016
Expenses:
Newsprint and supercalendered paper purchased from the Paper Mills	$ 2,300	$ 3,700	$ 7,700	$ 10,300
Madison Paper Industries
Schedule of Equity Method Investments [Line Items]
Revenues	0	0	0	40,523
Expenses:
Cost of sales	(105)	(1,450)	(1,277)	(68,039)
General and administrative income/(expense) and other	60,216	(566)	59,662	(66,056)
Total costs and expenses	60,111	(2,016)	58,385	(134,095)
Operating income/(loss)	60,111	(2,016)	58,385	(93,572)
Other (expense)/income	(1)	2	(7)	4
Net income/(loss)	$ 60,110	$ (2,014)	$ 58,378	$ (93,568)