Stockholders' Equity Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, beginning		$ (509,094)
Income tax (benefit)/expense		19,096	$ 16,988	$ (86,110)
Other comprehensive income/(loss), net of tax		29,239	24,788	(131,785)
Balance, ending		(479,816)	(509,094)
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, beginning		17
Other comprehensive income before reclassifications, before tax(1)	[1]	(3,070)
Amounts reclassified from accumulated other comprehensive loss, before tax(1)	[1]	0
Income tax (benefit)/expense	[1]	(1,231)
Other comprehensive income/(loss), net of tax		(1,839)
Balance, ending		(1,822)	17
Funded Status of Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, beginning		(509,111)
Other comprehensive income before reclassifications, before tax(1)	[1]	3,972
Amounts reclassified from accumulated other comprehensive loss, before tax(1)	[1]	47,472
Income tax (benefit)/expense	[1]	20,327
Other comprehensive income/(loss), net of tax		31,117
Balance, ending		(477,994)	(509,111)
Total Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, beginning		(509,094)
Other comprehensive income before reclassifications, before tax(1)	[1]	902
Amounts reclassified from accumulated other comprehensive loss, before tax(1)	[1]	47,472
Income tax (benefit)/expense	[1]	19,096
Other comprehensive income/(loss), net of tax		29,278	24,701	$ (131,184)
Balance, ending		$ (479,816)	$ (509,094)

[1] All amounts are shown net of noncontrolling interest.