Accumulated Other Comprehensive Income (Loss) and Shareholders' Equity (Components) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 563,259	$ 514,577
Other comprehensive income (loss) before reclassifications	550	1,377
Tax (expense) or benefit	100	(341)
Reclassification of stranded tax impact	0
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(352)	(87)
Ending balance	545,251	514,241
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(2,973)	31
Other comprehensive income (loss) before reclassifications	963	1
Tax (expense) or benefit	0	0
Reclassification of stranded tax impact	0
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	0
Ending balance	(2,010)	32
Unrealized Gains (Losses) on Marketable Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(156)	(132)
Other comprehensive income (loss) before reclassifications	114	(100)
Tax (expense) or benefit	(24)	21
Reclassification of stranded tax impact	0
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	0
Ending balance	(66)	(211)
Pension and Post-retirement Liabilities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(2,929)	(5,630)
Other comprehensive income (loss) before reclassifications	0	0
Tax (expense) or benefit	0	0
Reclassification of stranded tax impact	(1,185)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	0
Ending balance	(4,114)	(5,630)
Derivative Financial Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	2,459
Other comprehensive income (loss) before reclassifications	(527)
Tax (expense) or benefit	124
Reclassification of stranded tax impact	446
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(352)
Ending balance	2,150
Derivative Financial Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		2,120
Other comprehensive income (loss) before reclassifications		1,476
Tax (expense) or benefit		(362)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax		(87)
Ending balance		3,147
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(3,599)	(3,611)
Reclassification of stranded tax impact	(739)
Ending balance	$ (4,040)	$ (2,662)