Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 5,048	$ 6,698	$ 10,188	$ 18,417
Other comprehensive income (loss):
Change in net actuarial gain	28	26	85	78
Tax effect on change in net actuarial gain	(10)	(9)	(30)	(27)
Unrealized holding gains (losses) arising during the period	2,039	(10,821)	7,767	(7,858)
Tax effect on unrealized holding gains (losses) arising during the period	(714)	3,787	(2,718)	2,750
Reclassification adjustment for gains included in net income	(1,105)	(28)	(1,589)	(5,881)
Tax effect on reclassification adjustment for gains included in net income	387	10	556	2,058
Other comprehensive income (loss), net of tax	625	(7,035)	4,071	(8,880)
Comprehensive income	$ 5,673	$ (337)	$ 14,259	$ 9,537