Loans and Allowance For Loan Losses - Additional Information (Detail)	3 Months Ended	12 Months Ended
Mar. 31, 2020 USD ($) Loans	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest forgone on nonaccrual loans	$ 82,000	$ 89,000
Financing Receivable, Troubled Debt Restructuring	$ 624,000
Financing Receivable, Modifications, Number of Contracts \| Loans	0		0
Increase Decrease In Allowance For Loan And Lease Losses	$ 0	$ 0
Revolving Credit Facility [Member] \| One Year Prime Rate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt Instrument, Variable Interest Rate Basis	six month term at a rate of Prime plus 0.40%.		one-year at a rate of Prime plus 0.40%
Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Troubled Debt Restructuring			$ 722,000
Financing Receivables Impaired Troubled Debt Restructuring Specific Reserve	$ 20,000		$ 12,000

Financing Receivables, Impaired, Troubled Debt Restructuring, Specific Reserve.

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.

+ Details

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- Definition

Amount of increase (decrease) of allowance reserve for credit loss.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(d))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

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- Definition

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

+ References

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- Definition

Amount of financing receivable modified as troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953676-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=118939409&loc=d3e18845-111554

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- Definition

Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118939409&loc=d3e18794-111554

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