Accumulated Other Comprehensive Income (Loss) (Changes in AOCI Components) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2016	Sep. 26, 2015	Oct. 01, 2016	Sep. 26, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Loss, Beginning balance			$ (105,930)
Other comprehensive loss before reclassifications			(196)
Amounts reclassified from AOCI			9,805
Total other comprehensive income	$ 3,064	$ (460)	9,609	$ 985
Accumulated Other Comprehensive Loss, Ending balance	(96,321)		(96,321)
Foreign Currency Translation [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Loss, Beginning balance			(7,200)
Other comprehensive loss before reclassifications			(196)
Amounts reclassified from AOCI			2,338
Total other comprehensive income			2,142
Accumulated Other Comprehensive Loss, Ending balance	(5,058)		(5,058)
Pension and Other Postretirement Benefits [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Loss, Beginning balance			(98,730)
Other comprehensive loss before reclassifications			0
Amounts reclassified from AOCI			7,467
Total other comprehensive income			7,467
Accumulated Other Comprehensive Loss, Ending balance	$ (91,263)		$ (91,263)