Investment Securities - Gross unrealized losses (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Investment securities available-for-sale
Unrealized losses less than 12 months	$ (37)	$ (313)
Fair value less than 12 months	18,437	46,067
Unrealized losses over 12 months	(130)	(162)
Fair value over 12 months	8,623	36,019
Total Unrealized losses	(167)	(475)
Total Fair value	27,060	82,086
U. S. Treasury and agencies
Investment securities available-for-sale
Unrealized losses less than 12 months	(4)	(5)
Fair value less than 12 months	1,342	1,740
Unrealized losses over 12 months		(10)
Fair value over 12 months		9,990
Total Unrealized losses	(4)	(15)
Total Fair value	1,342	11,730
Obligations of state and political agencies
Investment securities available-for-sale
Unrealized losses less than 12 months	(27)	(140)
Fair value less than 12 months	12,420	11,959
Unrealized losses over 12 months		(21)
Fair value over 12 months		5,798
Total Unrealized losses	(27)	(161)
Total Fair value	12,420	17,757
Mortgage backed securities - Residential Agency
Investment securities available-for-sale
Unrealized losses less than 12 months	(5)	(52)
Fair value less than 12 months	2,664	17,131
Unrealized losses over 12 months	(13)	(79)
Fair value over 12 months	1,691	14,036
Total Unrealized losses	(18)	(131)
Total Fair value	4,355	31,167
Mortgage backed securities - Commercial
Investment securities available-for-sale
Unrealized losses less than 12 months		(116)
Fair value less than 12 months		15,235
Unrealized losses over 12 months	(117)	(52)
Fair value over 12 months	6,932	6,195
Total Unrealized losses	(117)	(168)
Total Fair value	6,932	21,430
Asset backed securities
Investment securities available-for-sale
Fair value less than 12 months	2	2
Total Fair value	2	$ 2
Corporate bonds
Investment securities available-for-sale
Unrealized losses less than 12 months	(1)
Fair value less than 12 months	2,009
Total Unrealized losses	(1)
Total Fair value	$ 2,009