Retirement Plans (Schedule of Fair Value, Assets Measured on Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets, excluding cash and cash equivalents	$ 10,853	$ 10,387
Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets, excluding cash and cash equivalents	2,875	3,410
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets, excluding cash and cash equivalents	7,978	6,977
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets, excluding cash and cash equivalents	7,978	6,977
Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets, excluding cash and cash equivalents	7,978	6,977
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets, excluding cash and cash equivalents	2,875	3,410
Fair Value, Inputs, Level 2 [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets, excluding cash and cash equivalents	$ 2,875	$ 3,410