Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Consolidated Statements of Comprehensive Income [Abstract]
Net income (loss)	$ 9,685	$ (1,560)	$ 15,422	$ (924)
Other comprehensive income:
Change in net actuarial gain	27	37	80	107
Tax effect on change in net actuarial gain	(6)	(13)	(17)	(37)
Unrealized holding gains arising during the period	342	308	1,909	8,208
Tax effect on unrealized holding gains arising during the period	(72)	(108)	(401)	(2,873)
Reclassification adjustment for (gains) losses included in net income	166	(3,188)	159	(5,679)
Tax effect on reclassification adjustment for (gains) losses included in net income	(35)	1,116	(33)	1,988
Other comprehensive income (loss), net of tax	422	(1,848)	1,697	1,714
Comprehensive income (loss)	$ 10,107	$ (3,408)	$ 17,119	$ 790