Accumulated Other Comprehensive Income (Loss) and Shareholders' Equity (Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	$ 514,577	$ 501,009	$ 477,299
Other comprehensive income (loss) before reclassifications	1,984	1,194	148
Tax (expense) or benefit	(1,173)	(14)	(590)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(799)	209	628
Ending Balance	563,259	514,577	501,009
Accumulated Other Comprehensive Income (Loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	(3,611)	(5,000)	(5,186)
Ending Balance	(3,599)	(3,611)	(5,000)
Foreign Currency Translation Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	31	(1,188)	322
Other comprehensive income (loss) before reclassifications	(3,004)	1,219	(1,510)
Tax (expense) or benefit	0	0	0
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	0	0
Ending Balance	(2,973)	31	(1,188)
Unrealized Gains (Losses) on Marketable Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	(132)	(105)	(2)
Other comprehensive income (loss) before reclassifications	(31)	(6)	(158)
Tax (expense) or benefit	7	(21)	55
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	0	0
Ending Balance	(156)	(132)	(105)
Pension and Post-retirement Liabilities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	(5,630)	(5,167)	(5,506)
Other comprehensive income (loss) before reclassifications	3,531	(733)	499
Tax (expense) or benefit	(830)	270	(160)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	0	0
Ending Balance	(2,929)	(5,630)	(5,167)
Derivative Financial Instruments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	2,120	1,460	0
Other comprehensive income (loss) before reclassifications	1,488	714	1,317
Tax (expense) or benefit	(350)	(263)	(485)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(799)	209	628
Ending Balance	$ 2,459	$ 2,120	$ 1,460