Number of days for demand deposits with financial institutions to be considered cash and cash equivalent.

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- Definition

Par value of Federal Home Loan Bank Stock.

+ References

No definition available.

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- Definition

Minimum balance requirement to perform detailed loan review.

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No definition available.

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- Definition

Percentage of insurance commission revenue of total revenue.

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No definition available.

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- Definition

Represents the number of days past due for loans and leases to be considered nonaccrual.

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No definition available.

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- Definition

Number of days secured residential real estate loans are past due to receive an assessment of value.

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No definition available.

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- Definition

Number of days unsecured loans are past due to recognize charge off.

+ References

No definition available.

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- Definition

Number of days all other loans are past due to recognize an impairment.

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No definition available.

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Significant Accounting Policies [Line Items]

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No definition available.

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- Definition

Cash deposited in a special reserve account for the exclusive benefit of customers pursuant to SEC Regulations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount of the cumulative effect on retained earnings net of related income tax effect.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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No definition available.

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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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Present value of lessee's discounted obligation for lease payments from operating lease.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-Section 45
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- Definition

Amount of lessee's right to use underlying asset under operating lease.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
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- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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No definition available.

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Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019 USD ($) Segment $ / shares	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019 USD ($)
Significant Accounting Policies [Line Items]
Allowance for loan losses related to commercial, commercial real estate and farm real estate loans	$ 750,000
Number of days reaching which loans are considered for nonaccrual status	90 days
Federal Home Loan Bank par value \| $ / shares	$ 100
Reserve amount	$ 7,127,000
Number of operating segments \| Segment	1
Right-of-use asset	$ 3,273,000			$ 2,210,000
Lease liability	3,273,000			$ 2,210,000
Change in accounting principle for adoption of ASU 2016-02	$ 0
Unsecured Debt [Member]
Significant Accounting Policies [Line Items]
Retail loans past due charge off period	90 days
Secured Debt [Member]
Significant Accounting Policies [Line Items]
Residential real estate loans past due assessment of value period	180 days
Other Debt [Member]
Significant Accounting Policies [Line Items]
Loans past due charged down to the net realizable value period	90 days
Maximum [Member]
Significant Accounting Policies [Line Items]
Percentage of insurance commission revenue of total revenue	1.00%	1.00%	1.00%
Original maturities for cash and cash equivalents	90 days
Estimated useful life of intangible assets	12 years
Maximum [Member] \| Furniture and Equipment [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of asset	7 years
Maximum [Member] \| Buildings and Improvements [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of asset	50 years
Maximum [Member] \| WSP [Member]
Significant Accounting Policies [Line Items]
Percentage of insurance commission revenue of total revenue	1.00%	1.00%	1.00%
Maximum [Member] \| CIVB Risk Management, Inc. [Member]
Significant Accounting Policies [Line Items]
Percentage of insurance commission revenue of total revenue	1.00%	1.00%	1.00%
Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of intangible assets	5 years
Minimum [Member] \| Furniture and Equipment [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of asset	3 years
Minimum [Member] \| Buildings and Improvements [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of asset	7 years