Supplemental Stockholders' Equity Information - Changes in Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Sep. 28, 2014		Sep. 29, 2013
Changes in accumulated other comprehensive income (loss):
Balance, beginning of period			$ (402,611)
Other comprehensive (loss)/income before reclassifications, before tax			(7,163)	[1]
Amounts reclassified from accumulated other comprehensive loss, before tax			20,190
Effect of other postretirement benefit remeasurement			13,756
Effect of other postretirement benefit remeasurement (2)			9,525
Income tax (benefit)/expense	9,410	4,196	14,551		9,648
Other comprehensive income, net of tax	13,886	6,684	21,757		14,211
Balance, end of period	(380,854)		(380,854)
Foreign Currency Translation Adjustments [Member]
Changes in accumulated other comprehensive income (loss):
Balance, beginning of period			12,674
Other comprehensive (loss)/income before reclassifications, before tax			(7,163)	[1]
Amounts reclassified from accumulated other comprehensive loss, before tax			0
Effect of other postretirement benefit remeasurement			0
Effect of other postretirement benefit remeasurement (2)			0
Income tax (benefit)/expense			(2,694)
Other comprehensive income, net of tax			(4,469)
Balance, end of period	8,205		8,205
Funded Status of Benefit Plans [Member]
Changes in accumulated other comprehensive income (loss):
Balance, beginning of period			(415,285)
Other comprehensive (loss)/income before reclassifications, before tax			0	[1]
Amounts reclassified from accumulated other comprehensive loss, before tax			20,190
Effect of other postretirement benefit remeasurement			13,756
Effect of other postretirement benefit remeasurement (2)			9,525
Income tax (benefit)/expense			17,245
Other comprehensive income, net of tax			26,226
Balance, end of period	$ (389,059)		$ (389,059)

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