Retirement Plans (Schedule of Fair Value, Assets Measured on Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets, excluding cash and cash equivalents	$ 9,381	$ 10,742
Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets, excluding cash and cash equivalents	3,468	3,586
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets, excluding cash and cash equivalents	5,913	7,156
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	5,913	7,156
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	5,913	7,156
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	3,468	3,586
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	$ 3,468	$ 3,586