Other (Income) Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Other Income and Expenses [Abstract]
Foreign currency (gains) losses	$ (7,560)	$ 3,096	$ (2,575)	$ 8,749
Pension benefit expense	3,096	2,809	6,230	5,618
Other items	(909)	(37)	(1,265)	(522)
Settlement of contract escrow				(2,247)
Total other (income) expense	$ (5,373)	$ 5,868	$ 2,390	$ 11,598