Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 4,419	$ 2,109	$ 1,409	$ 6,169
Unrealized gains (losses) on securities available-for-sale:
Unrealized holding gains (losses) arising during the period	526	(744)	2,433	2,829
Reclassification adjustment for gains (losses) included in net income	(9)	4	(42)	(121)
Tax effect	(198)	283	(915)	(1,037)
Net of tax	319	(457)	1,476	1,671
Unrealized losses on securities transferred to held-to-maturity:
Reclassification adjustment for losses included in net income	79	42	162	125
Tax effect	(30)	(16)	(62)	(48)
Net of tax	49	26	100	77
Unrealized gains (losses) on cash flow hedges:
Unrealized holding gains (losses) arising during the period	(29)	87	(242)	(1,760)
Reclassification adjustment for losses included in net income	278	88	589	261
Tax effect	(34)	(33)	49	674
Net of tax	215	142	396	(825)
Other comprehensive income (loss)	583	(289)	1,972	923
Comprehensive income	$ 5,002	$ 1,820	$ 3,381	$ 7,092