Retirement Plans (Schedule of Fair Value, Assets Measured on Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets, excluding cash and cash equivalents	$ 10,091	$ 10,120
Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets, excluding cash and cash equivalents	3,438	3,423
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets, excluding cash and cash equivalents	6,653	6,697
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	6,653	6,697
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	6,653	6,697
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	3,438	3,423
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	$ 3,438	$ 3,423