Changes in Accumulated Other Comprehensive Income Balances (Schedule of Changes in Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ 10,371
Other comprehensive income:
Change in net actuarial gain	$ 37	$ 28	107	$ 85
Tax effect on change in net actuarial gain	(13)	(10)	(37)	(30)
Net unrealized holding gains (losses) arising during the period	308	2,039	8,208	7,767
Tax effect on unrealized gains arising during the period	(108)	(714)	(2,873)	(2,718)
Reclassification adjustment for gains included in net realized gains (losses)	(3,188)	(1,105)	(5,679)	(1,589)
Tax effect on reclassification adjustment for gains (losses) included in net income	1,116	387	1,988	556
Other comprehensive income (loss), net of tax	(1,848)	625	1,714	4,071
Ending Balance	12,085		12,085
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			107	85
Tax effect on change in net actuarial gain			(37)	(30)
Other comprehensive income (loss), net of tax			70	55
Ending Balance	(2,596)	(2,517)	(2,596)	(2,517)
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			8,208	7,767
Tax effect on unrealized gains arising during the period			(2,873)	(2,718)
Reclassification adjustment for gains included in net realized gains (losses)			(5,679)	(1,589)
Tax effect on reclassification adjustment for gains (losses) included in net income			1,988	556
Other comprehensive income (loss), net of tax			1,644	4,016
Ending Balance	14,681	14,006	14,681	14,006
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			107	85
Tax effect on change in net actuarial gain			(37)	(30)
Net unrealized holding gains (losses) arising during the period			8,208	7,767
Tax effect on unrealized gains arising during the period			(2,873)	(2,718)
Reclassification adjustment for gains included in net realized gains (losses)			(5,679)	(1,589)
Tax effect on reclassification adjustment for gains (losses) included in net income			1,988	556
Other comprehensive income (loss), net of tax			1,714	4,071
Ending Balance	$ 12,085	$ 11,489	$ 12,085	$ 11,489