Securities Available for Sale - Gross unrealized losses and the related fair value of securities available for sale (Details) $ in Thousands	Sep. 30, 2020 USD ($) Security	Dec. 31, 2019 USD ($) Security
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	$ 14,307	$ 73,112
Less than 12 months, unrealized losses	64	379
12 months or more, fair value	481	65,967
12 months or more, unrealized losses	6	535
Total, fair value	14,788	139,079
Total, unrealized losses	$ 70	$ 914
Total, number of securities | Security	38	212
U.S. government agency securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value		$ 1,035
Less than 12 months, unrealized losses		2
12 months or more, fair value		11,091
12 months or more, unrealized losses		58
Total, fair value		12,126
Total, unrealized losses		$ 60
Total, number of securities | Security		6
State, county and municipals
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	$ 8,867	$ 22,451
Less than 12 months, unrealized losses	22	132
12 months or more, fair value	0	7,605
12 months or more, unrealized losses	0	25
Total, fair value	8,867	30,056
Total, unrealized losses	$ 22	$ 157
Total, number of securities | Security	18	56
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	$ 5,440	$ 49,626
Less than 12 months, unrealized losses	42	245
12 months or more, fair value	481	47,271
12 months or more, unrealized losses	6	452
Total, fair value	5,921	96,897
Total, unrealized losses	$ 48	$ 697
Total, number of securities | Security	20	150