Net Periodic Pension Cost (Schedule of Net Benefit Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Retirement Plans
Interest cost	$ 89	$ 113	$ 266	$ 340
Amortization of net loss	34	36	104	108
Expected return on plan assets	(171)	(149)	(513)	(448)
Net periodic pension cost	(48)	0	(143)	0
Contributed amount	$ 0	$ 500	$ 0	$ 500