Supplemental Equity Information - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 29, 2015
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	$ (130,951)	$ (778,769)
Other comprehensive income (loss) before reclassifications	(1,348)	(11,913)
Amounts reclassified from AOCL	1,162	9,645
Other comprehensive income (loss)	(186)	(2,268)
Ending Balance	(131,137)	(781,037)
Retirement Plans
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(116,496)	(1,172,245)
Other comprehensive income (loss) before reclassifications	0	14,831
Amounts reclassified from AOCL	1,162	9,645
Other comprehensive income (loss)	1,162	24,476
Ending Balance	(115,334)	(1,147,769)
Foreign Currency Translation
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(20,129)	391,113
Other comprehensive income (loss) before reclassifications	635	(26,744)
Amounts reclassified from AOCL	0	0
Other comprehensive income (loss)	635	(26,744)
Ending Balance	(19,494)	364,369
Other
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	5,674	2,363
Other comprehensive income (loss) before reclassifications	(1,983)	0
Amounts reclassified from AOCL	0	0
Other comprehensive income (loss)	(1,983)	0
Ending Balance	$ 3,691	$ 2,363