Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 18,864	$ 12,315	$ 13,241
Other Comprehensive Income (Loss)
Net unrealized holding gain (loss) on securities available for sale	(2,912)	3,112	(3,258)
Reclassification adjustment for realized gains included in net income	(804)	(708)	(1,023)
Net unrealized gain (loss) on derivative used for cash flow hedges			1
Net unrealized gain (loss) relating to defined benefit plan	(109)	(20)	62
Other comprehensive income, before tax, total	(3,825)	2,384	(4,218)
Income tax (benefit) expense related to other comprehensive income	820	(749)	1,474
Other comprehensive income (loss), net of tax	(3,005)	1,635	(2,744)
Comprehensive Income	$ 15,859	$ 13,950	$ 10,497