Loans and Allowance for Credit Losses on Loans - Transactions In The Allowance For Loan Losses ("ALL") (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Balance	$ 3,287	$ 3,642	$ 3,581	$ 3,590
Provision for credit losses	35		35	60
Charge-offs	(4)		(4)	(9)
Recoveries	1	2	2	3
Balance	3,319	3,644	3,319	3,644
ASU 2016-13 [Member] \| Impact of adopting ASC 326 [Member]
Balance			(295)
CRE [Member]
Balance	725	894	942	833
Provision for credit losses	81	125	18	186
Balance	806	1,019	806	1,019
CRE [Member] \| ASU 2016-13 [Member] \| Impact of adopting ASC 326 [Member]
Balance			(154)
MF [Member]
Balance	49	78	54	80
Provision for credit losses		(21)	(6)	(23)
Balance	49	57	49	57
MF [Member] \| ASU 2016-13 [Member] \| Impact of adopting ASC 326 [Member]
Balance			1
C+I [Member]
Balance	281	218	184	194
Provision for credit losses	(4)	(11)	4	13
Recoveries		1		1
Balance	277	208	277	208
C+I [Member] \| ASU 2016-13 [Member] \| Impact of adopting ASC 326 [Member]
Balance			89
ADL [Member]
Balance	96	116	138	178
Provision for credit losses	(26)	(6)	(50)	(68)
Balance	70	110	70	110
ADL [Member] \| ASU 2016-13 [Member] \| Impact of adopting ASC 326 [Member]
Balance			(18)
RES [Member]
Balance	1,904	2,188	2,048	2,139
Provision for credit losses	6	(163)	63	(114)
Balance	1,910	2,025	1,910	2,025
RES [Member] \| ASU 2016-13 [Member] \| Impact of adopting ASC 326 [Member]
Balance			(201)
HELOC [Member]
Balance	88	62	81	63
Provision for credit losses	(3)	25	(3)	24
Balance	85	87	85	87
HELOC [Member] \| ASU 2016-13 [Member] \| Impact of adopting ASC 326 [Member]
Balance			7
CON [Member]
Balance	119	86	100	75
Provision for credit losses	(7)	24	(3)	43
Charge-offs	(4)		(4)	(9)
Recoveries	1	1	2	2
Balance	109	111	109	111
CON [Member] \| ASU 2016-13 [Member] \| Impact of adopting ASC 326 [Member]
Balance			14
Unallocated [Member]
Balance	25		34	28
Provision for credit losses	(12)	27	12	(1)
Balance	$ 13	$ 27	13	$ 27
Unallocated [Member] \| ASU 2016-13 [Member] \| Impact of adopting ASC 326 [Member]
Balance			$ (33)

Provision (benefit) for loan losses.

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- Definition

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 11B
-Subparagraph (c)(4)
-SubTopic 10
-Topic 310
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-11B

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- Definition

Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 11B
-Subparagraph (c)(3)
-SubTopic 10
-Topic 310
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-11B

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- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)(1)(ii)
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-URI https://asc.fasb.org//1943274/2147481696/310-30-50-2

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-Name Accounting Standards Codification
-Section 50
-Paragraph 11B
-Subparagraph (g)
-SubTopic 10
-Topic 310
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-11B

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-Name Accounting Standards Codification
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 6.L.1)
-SubTopic 10
-Topic 310
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480418/310-10-S99-4

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