Investment Securities - Unrealized loss positions (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Marketable securities - Fair Value
Less than 12 months	$ 11,566	$ 21,538
12 months or more		6,489
Total	11,566	28,027
Marketable securities - Unrealized Loss
Less than 12 months	485	109
12 months or more		60
Total	485	169
Obligations of U.S. Government agencies
Debt securities - Fair Value
Less than 12 months		5,269
12 months or more		2,000
Total		7,269
Debt securities - Unrealized Loss
Less than 12 months		34
12 months or more		2
Total		36
Obligations of States and political subdivisions
Debt securities - Fair Value
Less than 12 months	9,027	4,669
Total	9,027	4,669
Debt securities - Unrealized Loss
Less than 12 months	409	43
Total	409	43
Mortgage-backed securities
Debt securities - Fair Value
Less than 12 months	1,587	11,600
12 months or more		4,489
Total	1,587	16,089
Debt securities - Unrealized Loss
Less than 12 months	33	32
12 months or more		58
Total	33	$ 90
Subordinated debt investments
Debt securities - Fair Value
Less than 12 months	952
Total	952
Debt securities - Unrealized Loss
Less than 12 months	43
Total	$ 43