Changes in Accumulated Other Comprehensive Income Balances (Schedule of Changes in Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ 10,371
Other comprehensive income:
Change in net actuarial gain	$ 35	$ 29	70	$ 57
Tax effect on change in net actuarial gain	(12)	(10)	(24)	(20)
Net unrealized holding gains (losses) arising during the period	2,654	4,358	7,900	5,729
Tax effect on unrealized gains arising during the period	(929)	(1,525)	(2,765)	(2,005)
Reclassification adjustment for gains included in net realized gains (losses)	10	(410)	(2,491)	(484)
Tax effect on reclassification adjustment for gains (losses) included in net income	(3)	143	872	169
Other comprehensive income (loss), net of tax	1,755	2,585	3,562	3,446
Ending Balance	13,933		13,933
Minimum Pension Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(2,666)	(2,572)
Other comprehensive income:
Change in net actuarial gain			70	57
Tax effect on change in net actuarial gain			(24)	(20)
Other comprehensive income (loss), net of tax			46	37
Ending Balance	(2,620)	(2,535)	(2,620)	(2,535)
Unrealized Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			13,037	9,990
Other comprehensive income:
Net unrealized holding gains (losses) arising during the period			7,900	5,729
Tax effect on unrealized gains arising during the period			(2,765)	(2,005)
Reclassification adjustment for gains included in net realized gains (losses)			(2,491)	(484)
Tax effect on reclassification adjustment for gains (losses) included in net income			872	169
Other comprehensive income (loss), net of tax			3,516	3,409
Ending Balance	16,553	13,399	16,553	13,399
Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			10,371	7,418
Other comprehensive income:
Change in net actuarial gain			70	57
Tax effect on change in net actuarial gain			(24)	(20)
Net unrealized holding gains (losses) arising during the period			7,900	5,729
Tax effect on unrealized gains arising during the period			(2,765)	(2,005)
Reclassification adjustment for gains included in net realized gains (losses)			(2,491)	(484)
Tax effect on reclassification adjustment for gains (losses) included in net income			872	169
Other comprehensive income (loss), net of tax			3,562	3,446
Ending Balance	$ 13,933	$ 10,864	$ 13,933	$ 10,864