Changes in Accumulated Other Comprehensive Income Balances (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ (6,660)
Other comprehensive income:
Change in net actuarial gain	$ 37	$ 26	72	$ 53
Tax effect on change in net actuarial gain	(8)	(5)	(15)	(11)
Unrealized holding gains (losses) arising during the period	3,460	2,321	11,233	1,926
Tax effect on unrealized gains arising during the period	(727)	(487)	(2,359)	(404)
Reclassification adjustment for realized (gain) losses included in investment gains and losses	(60)	(381)	(4,201)	(366)
Tax effect on reclassification adjustment for gains (losses) included in income tax expense	13	80	883	77
Other comprehensive income, net of tax	2,715	1,554	5,613	1,275
Reclassification of certain tax effects from accumulated other comprehensive income at January 1,2018					$ (2,600)
Ending Balance	(1,047)		(1,047)
Pension Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(3,334)	(2,310)
Other comprehensive income:
Change in net actuarial gain			72	53
Tax effect on change in net actuarial gain			(15)	(11)
Other comprehensive income, net of tax			57	42
Reclassification of certain tax effects from accumulated other comprehensive income at January 1,2018						$ (569)
Ending Balance	(3,277)	(2,837)	(3,277)	(2,837)
Unrealized Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(3,326)	14,544
Other comprehensive income:
Unrealized holding gains (losses) arising during the period			11,233	1,926
Tax effect on unrealized gains arising during the period			(2,359)	(404)
Reclassification adjustment for realized (gain) losses included in investment gains and losses			(4,201)	(366)
Tax effect on reclassification adjustment for gains (losses) included in income tax expense			883	77
Other comprehensive income, net of tax			5,556	1,233
Reclassification of certain tax effects from accumulated other comprehensive income at January 1,2018						3,188
Ending Balance	2,230	1,972	2,230	1,972
Unrealized Gain (Loss) [Member] | Accounting Standards Update 2016-01 [Member]
Other comprehensive income:
Cumulative effect of adoption of updated accounting guidance for equity financial instruments at January 1,2018						(16,993)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(6,660)	12,234
Other comprehensive income:
Change in net actuarial gain			72	53
Tax effect on change in net actuarial gain			(15)	(11)
Unrealized holding gains (losses) arising during the period			11,233	1,926
Tax effect on unrealized gains arising during the period			(2,359)	(404)
Reclassification adjustment for realized (gain) losses included in investment gains and losses			(4,201)	(366)
Tax effect on reclassification adjustment for gains (losses) included in income tax expense			883	77
Other comprehensive income, net of tax			5,613	1,275
Reclassification of certain tax effects from accumulated other comprehensive income at January 1,2018						2,619
Ending Balance	$ (1,047)	$ (865)	$ (1,047)	$ (865)
Accumulated Other Comprehensive Income (Loss) [Member] | Accounting Standards Update 2016-01 [Member]
Other comprehensive income:
Cumulative effect of adoption of updated accounting guidance for equity financial instruments at January 1,2018						$ (16,993)