Other Comprehensive Income Changes in accumulated other comprehensive income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Accumulated Other Comprehensive Income/(Loss) [Line Items]
Other than Temporary Impairment Loss, Investments, Portion in Other Comprehensive Loss, Tax, Attributable to Parent, Held-to-maturity Securities			$ (41,100)
Currency Translation Adjustment	$ 15,441	$ (20,194)	44,897	$ (40,169)
Accumulated Other Comprehensive Income [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax			(284,323)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			30,317
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	5,664	$ 505	14,838	(4,351)
Reclassification from accumulated other comprehensive income, current period, net of tax			(887)
Other Comprehensive Income (Loss), before Reclassifications, before Tax			29,430
Accumulated Other Comprehensive Income (Loss), Net of Tax	(254,893)		(254,893)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income/(Loss) [Line Items]
Currency Translation Adjustment			44,897
Accumulated Other Comprehensive Income [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax			(116,411)
Reclassification from accumulated other comprehensive income, current period, net of tax			0
Other Comprehensive Income (Loss), before Reclassifications, before Tax			44,897
Accumulated Other Comprehensive Income (Loss), Net of Tax	(71,514)		(71,514)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax			(173,394)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax			14,838
Reclassification from accumulated other comprehensive income, current period, net of tax			0
Other Comprehensive Income (Loss), before Reclassifications, before Tax			(14,838)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(188,232)		(188,232)
Interest Rate Swap [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax			5,482
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			258
Reclassification from accumulated other comprehensive income, current period, net of tax			(887)
Other Comprehensive Income (Loss), before Reclassifications, before Tax			(629)
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ 4,853		$ 4,853
Lynx [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Business Combination, Provisional Information Adjustment, Working Capital				$ 3,200