Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 4,173	$ 4,466
Other comprehensive income, before tax:
Amortization of unrecognized loss	0	2
Unrealized (losses) gains on investments arising during the period	(1,660)	1,666
Reclassification adjustment for sales of securities included in net income	0	(90)
Other comprehensive (loss) income, before tax	(1,660)	1,578
Income tax expense related to postretirement health benefits	0	1
Income tax (benefit) expense related to unrealized (losses) gains on investments arising during the period	(351)	569
Income tax benefit related to reclassification adjustment for sales of securities included in net income	0	(32)
Net income tax (benefit) expense on other comprehensive (loss) income	(351)	538
Other comprehensive (loss) income	(1,309)	1,040
Comprehensive Income	2,864	5,506
Comprehensive loss attributable to noncontrolling interests	3	10
Comprehensive Income Attributable to the Company	$ 2,867	$ 5,516