Loans and Allowance for Credit Losses - Troubled Debt Restructurings Identified During Period (Detail) $ in Thousands	3 Months Ended
Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($) Contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| Contract		2
Total Pre-Modification Outstanding Recorded Investment		$ 69
Post- Modification Outstanding Recorded Investment	$ 25	69
Troubled Debt Restructuring [Policy Text Block]		$ 0
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts \| Contract		1
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	0	$ 17
Residential real estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| Contract		2
Total Pre-Modification Outstanding Recorded Investment		$ 69
Post- Modification Outstanding Recorded Investment	25	69
Troubled Debt Restructuring [Policy Text Block]		$ 0
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts \| Contract		1
Financing Receivable, Troubled Debt Restructuring, Subsequent Default		$ 17
Senior Lien \| Residential real estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| Contract		2
Total Pre-Modification Outstanding Recorded Investment		$ 69
Post- Modification Outstanding Recorded Investment	25	69
Troubled Debt Restructuring [Policy Text Block]		$ 0
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts \| Contract		1
Financing Receivable, Troubled Debt Restructuring, Subsequent Default		$ 17
Extended Maturity [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Pre-Modification Outstanding Recorded Investment		0
Post- Modification Outstanding Recorded Investment	0
Extended Maturity [Member] \| Residential real estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Pre-Modification Outstanding Recorded Investment		0
Post- Modification Outstanding Recorded Investment	0
Extended Maturity [Member] \| Senior Lien \| Residential real estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Pre-Modification Outstanding Recorded Investment		0
Post- Modification Outstanding Recorded Investment	0
Contractual Interest Rate Reduction [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Pre-Modification Outstanding Recorded Investment		10
Post- Modification Outstanding Recorded Investment	25
Contractual Interest Rate Reduction [Member] \| Residential real estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Pre-Modification Outstanding Recorded Investment		10
Post- Modification Outstanding Recorded Investment	25
Contractual Interest Rate Reduction [Member] \| Senior Lien \| Residential real estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Pre-Modification Outstanding Recorded Investment		10
Post- Modification Outstanding Recorded Investment	$ 25
Contractual Payment Modification [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Pre-Modification Outstanding Recorded Investment		59
Contractual Payment Modification [Member] \| Residential real estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Pre-Modification Outstanding Recorded Investment		59
Contractual Payment Modification [Member] \| Senior Lien \| Residential real estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Pre-Modification Outstanding Recorded Investment		$ 59

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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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
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Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-33

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+ References

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
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Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
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