Loans and Allowance for Loan Losses - Troubled Debt and Modifications (Details)	12 Months Ended
Dec. 31, 2019 USD ($) item loan	Dec. 31, 2018 USD ($) item	Dec. 31, 2017 item
Troubled debt and modifications
Number of loans restructured during the last twelve months that defaulted during the period \| item	0	0	0
Commercial and commercial real estate
Troubled debt and modifications
Number of troubled debt restructuring \| item	0	1	1
Commercial and commercial real estate \| Modification of terms
Troubled debt and modifications
Recorded investment, before modification	$ 2,000,000	$ 2,000,000
Recorded investment, after modification	$ 2,000,000	$ 2,000,000
Residential real estate
Troubled debt and modifications
Number of loans in the process of foreclosure	1	0
Value of residential loans in process of foreclosure	$ 725,000

Number of financing receivables that are in the process of foreclosure.

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- Definition

The amount of residential loans in process of foreclosure.

+ References

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

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- Definition

Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

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- Definition

Pre-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524

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