Pensions and Other Postretirement Benefits (Schedule of Net Pension and Other Retirement Plan Costs) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Mar. 30, 2019
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Net service cost	$ 99	$ 83
Interest cost	129	157
Expected return on plan assets	(111)	(133)
Amortization of actuarial losses	77	50
Net periodic benefit cost	194	157
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Net service cost	31	31
Interest cost	33	45
Expected return on plan assets	0	0
Amortization of actuarial losses	34	39
Net periodic benefit cost	$ 98	$ 115