Net Periodic Pension Cost (Schedule of Net Benefit Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Retirement Plans
Interest cost	$ 88	$ 114	$ 177	$ 227
Amortization of net loss	35	36	70	72
Expected return on plan assets	(171)	(150)	(342)	(299)
Net periodic pension cost	(48)	0	(95)	0
Contributed amount	$ 0	$ 0	$ 0	$ 0