Accumulated Other Comprehensive Income (Loss) (Changes in AOCI Components) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Loss, Beginning balance			$ (101,886)
Other comprehensive income before reclassifications			410
Amounts reclassified from AOCI			7,854
Total other comprehensive income	$ 4,567	$ 3,064	8,264	$ 9,609
Accumulated Other Comprehensive Loss, Ending balance	(93,622)		(93,622)
Foreign Currency Translation [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Loss, Beginning balance			(5,255)
Other comprehensive income before reclassifications			410
Amounts reclassified from AOCI			0
Total other comprehensive income			410
Accumulated Other Comprehensive Loss, Ending balance	(4,845)		(4,845)
Pension and Other Postretirement Benefits [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Loss, Beginning balance			(96,631)
Other comprehensive income before reclassifications			0
Amounts reclassified from AOCI			7,854
Total other comprehensive income			7,854
Accumulated Other Comprehensive Loss, Ending balance	$ (88,777)		$ (88,777)