Securities Available for Sale - Gross unrealized losses and the related fair value of securities available for sale (Details) $ in Thousands	Mar. 31, 2020 USD ($) Security	Dec. 31, 2019 USD ($) Security
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	$ 38,324	$ 73,112
Less than 12 months, unrealized losses	277	379
12 months or more, fair value	28,683	65,967
12 months or more, unrealized losses	305	535
Total, fair value	67,007	139,079
Total, unrealized losses	$ 582	$ 914
Total, number of securities | Security	91	212
U.S. government agency securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	$ 0	$ 1,035
Less than 12 months, unrealized losses	0	2
12 months or more, fair value	10,854	11,091
12 months or more, unrealized losses	216	58
Total, fair value	10,854	12,126
Total, unrealized losses	$ 216	$ 60
Total, number of securities | Security	2	6
State, county and municipals
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	$ 12,286	$ 22,451
Less than 12 months, unrealized losses	25	132
12 months or more, fair value	0	7,605
12 months or more, unrealized losses	0	25
Total, fair value	12,286	30,056
Total, unrealized losses	$ 25	$ 157
Total, number of securities | Security	30	56
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	$ 9,261	$ 49,626
Less than 12 months, unrealized losses	32	245
12 months or more, fair value	17,829	47,271
12 months or more, unrealized losses	89	452
Total, fair value	27,090	96,897
Total, unrealized losses	$ 121	$ 697
Total, number of securities | Security	50	150
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	$ 16,777	$ 0
Less than 12 months, unrealized losses	220	0
12 months or more, fair value	0	0
12 months or more, unrealized losses	0	0
Total, fair value	16,777	0
Total, unrealized losses	$ 220	$ 0
Total, number of securities | Security	9	0