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Securities - Unrealized Loss Positions (Details)	Sep. 30, 2019 USD ($) security	Dec. 31, 2018 USD ($) security
Securities Available-for-Sale, Number of Securities
Less than 12 months in an unrealized loss position | security	15	16
Greater than 12 months in an unrealized loss position | security	16	61
Total	31	77
Securities Available-for-Sale, Unrealized Losses
Less than 12 months in an unrealized loss position	$ 534,000	$ 1,256,000
Greater than 12 months in an unrealized loss position	1,015,000	7,592,000
Total	1,549,000	8,848,000
Securities Available-for-Sale, Fair Value
Less than 12 months in an unrealized loss position	84,211,000	86,856,000
Greater than 12 months in an unrealized loss position	47,323,000	197,238,000
Total	$ 131,534,000	$ 284,094,000
US Treasury Securities [Member]
Securities Available-for-Sale, Number of Securities
Greater than 12 months in an unrealized loss position | security		1
Total		1
Securities Available-for-Sale, Unrealized Losses
Greater than 12 months in an unrealized loss position		$ 83,000
Total		83,000
Securities Available-for-Sale, Fair Value
Greater than 12 months in an unrealized loss position		3,923,000
Total		$ 3,923,000
US Government Corporations and Agencies Securities [Member]
Securities Available-for-Sale, Number of Securities
Less than 12 months in an unrealized loss position | security		3
Greater than 12 months in an unrealized loss position | security	4	1
Total	4	4
Securities Available-for-Sale, Unrealized Losses
Less than 12 months in an unrealized loss position		$ 100,000
Greater than 12 months in an unrealized loss position	$ 161,000	61,000
Total	161,000	161,000
Securities Available-for-Sale, Fair Value
Less than 12 months in an unrealized loss position		7,385,000
Greater than 12 months in an unrealized loss position	9,143,000	3,566,000
Total	$ 9,143,000	$ 10,951,000
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	3
Greater than 12 months in an unrealized loss position | security	2	11
Total	5	11
Securities Available-for-Sale, Unrealized Losses
Less than 12 months in an unrealized loss position	$ 7,000
Greater than 12 months in an unrealized loss position	10,000	$ 377,000
Total	17,000	377,000
Securities Available-for-Sale, Fair Value
Less than 12 months in an unrealized loss position	3,044,000
Greater than 12 months in an unrealized loss position	848,000	11,439,000
Total	$ 3,892,000	$ 11,439,000
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	3	4
Greater than 12 months in an unrealized loss position | security	2	33
Total	5	37
Securities Available-for-Sale, Unrealized Losses
Less than 12 months in an unrealized loss position	$ 326,000	$ 126,000
Greater than 12 months in an unrealized loss position	589,000	4,835,000
Total	915,000	4,961,000
Securities Available-for-Sale, Fair Value
Less than 12 months in an unrealized loss position	15,526,000	17,713,000
Greater than 12 months in an unrealized loss position	6,757,000	110,326,000
Total	$ 22,283,000	$ 128,039,000
Collateralized Mortgage Obligations [Member]
Securities Available-for-Sale, Number of Securities
Less than 12 months in an unrealized loss position | security	2	2
Greater than 12 months in an unrealized loss position | security	3	10
Total	5	12
Securities Available-for-Sale, Unrealized Losses
Less than 12 months in an unrealized loss position	$ 44,000	$ 309,000
Greater than 12 months in an unrealized loss position	16,000	1,835,000
Total	60,000	2,144,000
Securities Available-for-Sale, Fair Value
Less than 12 months in an unrealized loss position	9,320,000	15,211,000
Greater than 12 months in an unrealized loss position	2,332,000	43,687,000
Total	$ 11,652,000	$ 58,898,000
Asset-backed Securities [Member]
Securities Available-for-Sale, Number of Securities
Less than 12 months in an unrealized loss position | security	2
Greater than 12 months in an unrealized loss position | security	1	4
Total	3	4
Securities Available-for-Sale, Unrealized Losses
Less than 12 months in an unrealized loss position	$ 101,000
Greater than 12 months in an unrealized loss position	66,000	$ 225,000
Total	167,000	225,000
Securities Available-for-Sale, Fair Value
Less than 12 months in an unrealized loss position	29,389,000
Greater than 12 months in an unrealized loss position	3,213,000	16,473,000
Total	$ 32,602,000	$ 16,473,000
Collateralized loan obligations
Securities Available-for-Sale, Number of Securities
Less than 12 months in an unrealized loss position | security	5	7
Greater than 12 months in an unrealized loss position | security	4	1
Total	9	8
Securities Available-for-Sale, Unrealized Losses
Less than 12 months in an unrealized loss position	$ 56,000	$ 721,000
Greater than 12 months in an unrealized loss position	173,000	176,000
Total	229,000	897,000
Securities Available-for-Sale, Fair Value
Less than 12 months in an unrealized loss position	26,932,000	46,547,000
Greater than 12 months in an unrealized loss position	25,030,000	7,824,000
Total	$ 51,962,000	$ 54,371,000

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