Supplemental Stockholders' Equity Information Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2016	Jun. 28, 2015	Jun. 26, 2016	Jun. 28, 2015
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 27, 2015			$ (509,094)
Income tax expense(1)	$ 2,477	$ 4,256	5,580	$ 20,576
Other comprehensive income, net of tax	3,938	$ 6,793	9,029	31,284
Balance as of June 26, 2016	(500,065)		(500,065)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 27, 2015			17
Other comprehensive income before reclassifications, before tax(1)			1,506
Amounts reclassified from accumulated other comprehensive loss, before tax(1)			0
Income tax expense(1)			366
Other comprehensive income, net of tax			1,140
Balance as of June 26, 2016	1,157		1,157
Funded Status of Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 27, 2015			(509,111)
Other comprehensive income before reclassifications, before tax(1)			0
Amounts reclassified from accumulated other comprehensive loss, before tax(1)			13,103
Income tax expense(1)			5,214
Other comprehensive income, net of tax			7,889
Balance as of June 26, 2016	(501,222)		(501,222)
Total Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 27, 2015			(509,094)
Other comprehensive income before reclassifications, before tax(1)			1,506
Amounts reclassified from accumulated other comprehensive loss, before tax(1)			13,103
Income tax expense(1)			5,580
Other comprehensive income, net of tax			9,029	$ 31,233
Balance as of June 26, 2016	$ (500,065)		$ (500,065)