Other Comprehensive Income Changes in accumulated other comprehensive income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Accumulated Other Comprehensive Income/(Loss) [Line Items]
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax			$ 1,600
Other than Temporary Impairment Loss, Investments, Portion in Other Comprehensive Loss, Tax, Attributable to Parent, Held-to-maturity Securities			(42,000)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax			5,400
Currency Translation Adjustment	$ (41,963)	$ 18,621	(20,161)	$ 29,456
Accumulated Other Comprehensive Income [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax			(266,419)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			(4,797)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	(13,754)	$ 6,647	(4,880)	$ 9,174
Reclassification from accumulated other comprehensive income, current period, net of tax			248
Other Comprehensive Income (Loss), before Reclassifications, before Tax			(5,681)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(272,100)		(272,100)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax			1,100
Stranded Tax Effects Reclassified from OCI to Retained Earnings	1,132		1,132
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income/(Loss) [Line Items]
Currency Translation Adjustment			(20,161)
Accumulated Other Comprehensive Income [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax			(69,721)
Reclassification from accumulated other comprehensive income, current period, net of tax			0
Other Comprehensive Income (Loss), before Reclassifications, before Tax			(20,161)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(89,882)		(89,882)
Stranded Tax Effects Reclassified from OCI to Retained Earnings	0		0
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax			(203,063)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax			(4,393)
Reclassification from accumulated other comprehensive income, current period, net of tax			0
Other Comprehensive Income (Loss), before Reclassifications, before Tax			4,880
Accumulated Other Comprehensive Income (Loss), Net of Tax	(198,183)		(198,183)
Stranded Tax Effects Reclassified from OCI to Retained Earnings	(487)		(487)
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			6,365
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			10,971
Reclassification from accumulated other comprehensive income, current period, net of tax			248
Other Comprehensive Income (Loss), before Reclassifications, before Tax			9,600
Accumulated Other Comprehensive Income (Loss), Net of Tax	15,965		15,965
Stranded Tax Effects Reclassified from OCI to Retained Earnings	$ 1,619		$ 1,619