Allowance for Loan Losses - Impaired Loans - Average Recorded Investment and Interest Income Recognized (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Impaired [Line Items]
Nonaccrual loans with a related ACL	$ 1,198
Nonaccrual loans without a related ACL	11,269
Total Nonaccrual loans	12,467	$ 6,507
Average Recorded Investment	1,522	1,632
Interest Income Recognized	73	74
Interest Income Recognized	46
Commercial and Agriculture [Member]
Financing Receivable, Impaired [Line Items]
Nonaccrual loans with a related ACL	914
Nonaccrual loans without a related ACL	4,891
Total Nonaccrual loans	5,805	774
Average Recorded Investment	86	15
Interest Income Recognized	3	0
Interest Income Recognized	9
Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Nonaccrual loans with a related ACL	269
Nonaccrual loans without a related ACL	3
Total Nonaccrual loans	272	386
Average Recorded Investment	406	396
Interest Income Recognized	22	18
Interest Income Recognized	7
Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Nonaccrual loans without a related ACL	1,167
Total Nonaccrual loans	1,167	1,109
Average Recorded Investment	35	23
Interest Income Recognized	1	1
Residential Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Nonaccrual loans without a related ACL	4,633
Total Nonaccrual loans	4,633	3,926
Average Recorded Investment	614	629
Interest Income Recognized	33	31
Interest Income Recognized	26
Real Estate Construction [Member]
Financing Receivable, Impaired [Line Items]
Nonaccrual loans without a related ACL	41
Total Nonaccrual loans	41	221
Farm Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	381	569
Interest Income Recognized	14	24
Consumer and Other [Member]
Financing Receivable, Impaired [Line Items]
Nonaccrual loans without a related ACL	42
Total Nonaccrual loans	42	$ 91
Interest Income Recognized	$ 4

Financing receivable nonaccrual with allowance.

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

Amount of interest income on financing receivable on nonaccrual status.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-16

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- Definition

Amortized cost of financing receivable on nonaccrual status with no allowance for credit loss. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-16

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- Definition

Amortized cost of financing receivable on nonaccrual status. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph (a)
-Subparagraph (3)
-Publisher SEC

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph (a)
-Subparagraph (2)
-Publisher SEC

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-7

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- Definition

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
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-URI https://asc.fasb.org//1943274/2147481962/310-10-50-15

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-Section 50
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-17

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- Definition

Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
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-URI https://asc.fasb.org//1943274/2147481962/310-10-50-15

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