Loans and Allowance for Loan Losses - Additional Information (Details)	3 Months Ended
Mar. 31, 2019 USD ($) Contract	Mar. 31, 2018 USD ($) Contract	Dec. 31, 2018 USD ($)
Loans And Leases Receivable Disclosure [Line Items]
Minimum loan amount for loans analyzed by credit risk		$ 500,000
Total loans	$ 1,467,786,000		$ 1,429,794,000
Interest income recognized on a cash basis for impaired loans	0	$ 10,000
Investment in TDR	1,300,000		1,400,000
Specific allowance related to loans	191,000
Additional commitments related to TDR	$ 0		0
New TDR identified during the period \| Contract	0	0
TDR, payment default within twelve months \| Contract	0	0
Loan period considered as payment default	30 days
Troubled Debt Restructurings
Loans And Leases Receivable Disclosure [Line Items]
Specific allowance related to loans	$ 0		0
Doubtful
Loans And Leases Receivable Disclosure [Line Items]
Total loans	$ 0		$ 0

Financing receivables modifications past due default terms.

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- Definition

Loans and leases receivable impaired additional commitment to lend.

+ References

No definition available.

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- Definition

Minimum loan amount for loans analyzed by credit risk.

+ References

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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

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
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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.

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Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

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Amount of allowance for credit losses related to recorded investment.

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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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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

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-SubTopic 10
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