Accumulated Other Comprehensive Income (Loss) and Shareholders' Equity (Components) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 563,259	$ 514,577
Other comprehensive income (loss) before reclassifications	(2,359)	524
Tax (expense) or benefit	594	(609)
Reclassification of stranded tax impact	0
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(947)	(499)
Ending balance	560,345	553,074
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	(406)	(1,944)
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	(3,379)	(1,913)
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	319	(125)
Tax (expense) or benefit	(67)	26
Reclassification of stranded tax impact	0
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	0
Ending balance	96	(231)
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	(2,272)
Tax (expense) or benefit	661
Reclassification of stranded tax impact	446
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(947)
Ending balance	347
Derivative Financial Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		2,120
Other comprehensive income (loss) before reclassifications		2,593
Tax (expense) or benefit		(635)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax		(499)
Ending balance		3,579
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	$ (7,050)	$ (4,195)