Summary of Significant Accounting Policies - Summary of impact of the adoption (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 31, 2023	Jan. 01, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Assets [Abstract]
Allowance for credit losses on loans	$ 3,319	$ 3,287		$ 3,581	$ 3,644	$ 3,642	$ 3,590
Liabilities [Abstract]
Allowance for credit losses on OBS credit exposures	323,000			18,000
ASU 2016-13 [Member] \| As reported under ASC 326 [Member]
Assets [Abstract]
Allowance for credit losses on loans			$ 3,286
Liabilities [Abstract]
Allowance for credit losses on OBS credit exposures			308
ASU 2016-13 [Member] \| Pre-ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			3,581
Liabilities [Abstract]
Allowance for credit losses on OBS credit exposures			18
ASU 2016-13 [Member] \| Impact of ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			(295)	(295)
Liabilities [Abstract]
Allowance for credit losses on OBS credit exposures			290
CRE [Member]
Assets [Abstract]
Allowance for credit losses on loans	806	725		942	1,019	894	833
CRE [Member] \| ASU 2016-13 [Member] \| As reported under ASC 326 [Member]
Assets [Abstract]
Allowance for credit losses on loans			788
CRE [Member] \| ASU 2016-13 [Member] \| Pre-ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			942
CRE [Member] \| ASU 2016-13 [Member] \| Impact of ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			(154)	(154)
MF [Member]
Assets [Abstract]
Allowance for credit losses on loans	49	49		54	57	78	80
MF [Member] \| ASU 2016-13 [Member] \| As reported under ASC 326 [Member]
Assets [Abstract]
Allowance for credit losses on loans			55
MF [Member] \| ASU 2016-13 [Member] \| Pre-ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			54
MF [Member] \| ASU 2016-13 [Member] \| Impact of ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			1	1
C+I [Member]
Assets [Abstract]
Allowance for credit losses on loans	277	281		184	208	218	194
C+I [Member] \| ASU 2016-13 [Member] \| As reported under ASC 326 [Member]
Assets [Abstract]
Allowance for credit losses on loans			273
C+I [Member] \| ASU 2016-13 [Member] \| Pre-ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			184
C+I [Member] \| ASU 2016-13 [Member] \| Impact of ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			89	89
ADL [Member]
Assets [Abstract]
Allowance for credit losses on loans	70	96		138	110	116	178
ADL [Member] \| ASU 2016-13 [Member] \| As reported under ASC 326 [Member]
Assets [Abstract]
Allowance for credit losses on loans			120
ADL [Member] \| ASU 2016-13 [Member] \| Pre-ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			138
ADL [Member] \| ASU 2016-13 [Member] \| Impact of ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			(18)	(18)
RES [Member]
Assets [Abstract]
Allowance for credit losses on loans	1,910	1,904		2,048	2,025	2,188	2,139
RES [Member] \| ASU 2016-13 [Member] \| As reported under ASC 326 [Member]
Assets [Abstract]
Allowance for credit losses on loans			1,847
RES [Member] \| ASU 2016-13 [Member] \| Pre-ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			2,048
RES [Member] \| ASU 2016-13 [Member] \| Impact of ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			(201)	(201)
HELOC [Member]
Assets [Abstract]
Allowance for credit losses on loans	85	88		81	87	62	63
HELOC [Member] \| ASU 2016-13 [Member] \| As reported under ASC 326 [Member]
Assets [Abstract]
Allowance for credit losses on loans			88
HELOC [Member] \| ASU 2016-13 [Member] \| Pre-ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			81
HELOC [Member] \| ASU 2016-13 [Member] \| Impact of ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			7	7
CON [Member]
Assets [Abstract]
Allowance for credit losses on loans	109	119		100	111	$ 86	75
CON [Member] \| ASU 2016-13 [Member] \| As reported under ASC 326 [Member]
Assets [Abstract]
Allowance for credit losses on loans			114
CON [Member] \| ASU 2016-13 [Member] \| Pre-ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			100
CON [Member] \| ASU 2016-13 [Member] \| Impact of ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			14	14
Unallocated [Member]
Assets [Abstract]
Allowance for credit losses on loans	$ 13	$ 25		34	$ 27		$ 28
Unallocated [Member] \| ASU 2016-13 [Member] \| As reported under ASC 326 [Member]
Assets [Abstract]
Allowance for credit losses on loans			1
Unallocated [Member] \| ASU 2016-13 [Member] \| Pre-ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			34
Unallocated [Member] \| ASU 2016-13 [Member] \| Impact of ASC 326 Adoption [Member]
Assets [Abstract]
Allowance for credit losses on loans			$ (33)	$ (33)