Securities - Gross unrealised losses on investment securities - HTM (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Held-to-maturity Securities [Abstract]
Less than Twelve Months, Fair Value	$ 0	$ 1,039
Less than Twelve Months, Unrealized Losses	0	4
Twelve Months or More, Fair Value	0	3,186
Twelve Months or More, Unrealized Losses	0	53
Fair Value	0	4,225
Total Unrealized Losses	0	57
Mortgage-backed securities - residential
Held-to-maturity Securities [Abstract]
Less than Twelve Months, Fair Value	0	0
Less than Twelve Months, Unrealized Losses	0	0
Twelve Months or More, Fair Value	0	165
Twelve Months or More, Unrealized Losses	0	1
Fair Value	0	165
Total Unrealized Losses	0	1
State and political subdivisions
Held-to-maturity Securities [Abstract]
Less than Twelve Months, Fair Value	0	1,039
Less than Twelve Months, Unrealized Losses	0	4
Twelve Months or More, Fair Value	0	3,021
Twelve Months or More, Unrealized Losses	0	52
Fair Value	0	4,060
Total Unrealized Losses	$ 0	$ 56

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- Definition

Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in continuous loss position for 12 months or longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27337-111563

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27290-111563

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- Definition

Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position.

+ References

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Fair value of investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position.

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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in continuous loss position for less than 12 months.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27290-111563

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-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27337-111563

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Fair value of investment in debt security measured at amortized cost (held-to-maturity), in continuous unrealized loss position for less than 12 months.

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Fair value of investment in debt security measured at amortized cost (held-to-maturity), in continuous unrealized loss position for 12 months or longer.

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