Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 14,495	$ 5,500	$ 7,484	$ 12,126
Other comprehensive income, before tax:
Accumulated postretirement benefit obligation adjustment	0	0	(41)	0
Net unrealized gain on investments arising during the period	1,423	966	1,032	2,416
Reclassification adjustment for sale of securities included in net income	0	0	(30)	0
Reclassification adjustment for write-down of securities included in net income	0	0	482	0
Other comprehensive income, before tax	1,423	966	1,443	2,416
Income tax benefit related to postretirement health benefits	0	0	(9)	0
Income tax expense related to net unrealized gain on investments arising during the period	305	204	218	511
Income tax benefit related to reclassification adjustment for sale of securities included in net income	0	0	(6)	0
Income tax expense related to reclassification adjustment for write-down of securities included in net income	0	0	110	0
Net income tax expense on other comprehensive income	305	204	313	511
Other comprehensive income	1,118	762	1,130	1,905
Comprehensive Income	$ 15,613	$ 6,262	$ 8,614	$ 14,031