Securities - Unrealized Loss Positions (Details)	Sep. 30, 2020 USD ($) security	Dec. 31, 2019 USD ($) security
Securities Available-for-Sale, Number of Securities
Less than 12 months in an unrealized loss position | security	11	19
Greater than 12 months in an unrealized loss position | security	13	15
Total	24	34
Securities Available-for-Sale, Unrealized Losses
Less than 12 months in an unrealized loss position	$ 971,000	$ 2,602,000
Greater than 12 months in an unrealized loss position	2,412,000	1,181,000
Total	3,383,000	3,783,000
Securities Available-for-Sale, Fair Value
Less than 12 months in an unrealized loss position	38,266,000	129,582,000
Greater than 12 months in an unrealized loss position	65,470,000	45,240,000
Total	$ 103,736,000	$ 174,822,000
US Government Corporations and Agencies Securities [Member]
Securities Available-for-Sale, Number of Securities
Greater than 12 months in an unrealized loss position | security	4	4
Total	4	4
Securities Available-for-Sale, Unrealized Losses
Greater than 12 months in an unrealized loss position	$ 164,000	$ 165,000
Total	164,000	165,000
Securities Available-for-Sale, Fair Value
Greater than 12 months in an unrealized loss position	7,005,000	8,337,000
Total	$ 7,005,000	$ 8,337,000
Mortgage Backed Securities, Issued by US Government Agencies [Member]
Securities Available-for-Sale, Number of Securities
Less than 12 months in an unrealized loss position | security	1	3
Greater than 12 months in an unrealized loss position | security		2
Total	1	5
Securities Available-for-Sale, Unrealized Losses
Less than 12 months in an unrealized loss position	$ 2,000	$ 10,000
Greater than 12 months in an unrealized loss position		9,000
Total	2,000	19,000
Securities Available-for-Sale, Fair Value
Less than 12 months in an unrealized loss position	260,000	3,018,000
Greater than 12 months in an unrealized loss position		843,000
Total	$ 260,000	$ 3,861,000
US States and Political Subdivisions Debt Securities [Member]
Securities Available-for-Sale, Number of Securities
Less than 12 months in an unrealized loss position | security		6
Greater than 12 months in an unrealized loss position | security	1	2
Total	1	8
Securities Available-for-Sale, Unrealized Losses
Less than 12 months in an unrealized loss position		$ 1,665,000
Greater than 12 months in an unrealized loss position	$ 955,000	766,000
Total	955,000	2,431,000
Securities Available-for-Sale, Fair Value
Less than 12 months in an unrealized loss position		41,043,000
Greater than 12 months in an unrealized loss position	3,872,000	6,593,000
Total	$ 3,872,000	$ 47,636,000
Collateralized Mortgage Obligations [Member]
Securities Available-for-Sale, Number of Securities
Less than 12 months in an unrealized loss position | security	4	2
Greater than 12 months in an unrealized loss position | security	1	2
Total	5	4
Securities Available-for-Sale, Unrealized Losses
Less than 12 months in an unrealized loss position	$ 421,000	$ 26,000
Greater than 12 months in an unrealized loss position	2,000	12,000
Total	423,000	38,000
Securities Available-for-Sale, Fair Value
Less than 12 months in an unrealized loss position	8,027,000	9,054,000
Greater than 12 months in an unrealized loss position	279,000	1,209,000
Total	$ 8,306,000	$ 10,263,000
Asset-backed Securities [Member]
Securities Available-for-Sale, Number of Securities
Less than 12 months in an unrealized loss position | security	5	4
Greater than 12 months in an unrealized loss position | security	3	1
Total	8	5
Securities Available-for-Sale, Unrealized Losses
Less than 12 months in an unrealized loss position	$ 425,000	$ 839,000
Greater than 12 months in an unrealized loss position	881,000	48,000
Total	1,306,000	887,000
Securities Available-for-Sale, Fair Value
Less than 12 months in an unrealized loss position	22,603,000	54,540,000
Greater than 12 months in an unrealized loss position	33,069,000	3,238,000
Total	$ 55,672,000	$ 57,778,000
Collateralized loan obligations
Securities Available-for-Sale, Number of Securities
Less than 12 months in an unrealized loss position | security	1	4
Greater than 12 months in an unrealized loss position | security	4	4
Total	5	8
Securities Available-for-Sale, Unrealized Losses
Less than 12 months in an unrealized loss position	$ 123,000	$ 62,000
Greater than 12 months in an unrealized loss position	410,000	181,000
Total	533,000	243,000
Securities Available-for-Sale, Fair Value
Less than 12 months in an unrealized loss position	7,376,000	21,927,000
Greater than 12 months in an unrealized loss position	21,245,000	25,020,000
Total	$ 28,621,000	$ 46,947,000