Accumulated Other Comprehensive Income (Loss) - Summary of Significant Amounts Reclassified out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Net (gain) loss on sale of securities			$ 2	$ 42
Interest expense - Federal Home Loan Bank advances	$ (698)	$ (563)	(1,813)	(1,083)
Income tax benefit	(554)	(1,516)	(1,702)	(141)
Net income	3,656	4,419	10,363	1,409
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Losses on Cash Flow Hedges
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Interest expense money market	(111)	(109)	(330)	(322)
Interest expense - Federal Home Loan Bank advances	(108)	(168)	(368)	(267)
Income tax benefit	16		56
Net income	(203)	(277)	(642)	(589)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains and Losses on Available for Sale Securities
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Net (gain) loss on sale of securities	1	(9)	(2)	(42)
Income tax benefit		3	1	16
Net income	$ 1	(6)	(1)	(26)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Losses on Securities Transferred to Held to Maturity
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Interest income - securities		79	14	162
Income tax benefit		(30)	(4)	(62)
Net income		$ 49	$ 10	$ 100