Changes in Accumulated Other Comprehensive Income Balances (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 688
Other comprehensive (loss) income:
Change in net actuarial gain	34	$ 35
Tax effect on change in net actuarial gain	(7)	(7)
Unrealized holding gains (losses) arising during the period	(6,987)	7,773
Tax effect on unrealized holding gains (losses) arising during the period	1,467	(1,632)
Reclassification adjustment for gains included in net realized gains	(5,636)	(4,141)
Tax effect on reclassification adjustment for gains included in income tax expense	1,184	870
Other comprehensive income (loss), net of tax	(9,945)	2,898
Ending Balance	(9,257)
Pension Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(3,239)	(3,334)
Other comprehensive (loss) income:
Change in net actuarial gain	34	35
Tax effect on change in net actuarial gain	(7)	(7)
Other comprehensive income (loss), net of tax	27	28
Ending Balance	(3,212)	(3,306)
Unrealized Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	3,927	(3,326)
Other comprehensive (loss) income:
Unrealized holding gains (losses) arising during the period	(6,987)	7,773
Tax effect on unrealized holding gains (losses) arising during the period	1,467	(1,632)
Reclassification adjustment for gains included in net realized gains	(5,636)	(4,141)
Tax effect on reclassification adjustment for gains included in income tax expense	1,184	870
Other comprehensive income (loss), net of tax	(9,972)	2,870
Ending Balance	(6,045)	(456)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	688	(6,660)
Other comprehensive (loss) income:
Change in net actuarial gain	34	35
Tax effect on change in net actuarial gain	(7)	(7)
Unrealized holding gains (losses) arising during the period	(6,987)	7,773
Tax effect on unrealized holding gains (losses) arising during the period	1,467	(1,632)
Reclassification adjustment for gains included in net realized gains	(5,636)	(4,141)
Tax effect on reclassification adjustment for gains included in income tax expense	1,184	870
Other comprehensive income (loss), net of tax	(9,945)	2,898
Ending Balance	$ (9,257)	$ (3,762)