Loans - Information About Loans And The ALL By Portfolio Segment Are Summarized (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Individually evaluated for impairment	$ 921	$ 969
Collectively evaluated for impairment	377,088	374,022
Total	378,009	374,991
Collectively evaluated for impairment	3,642	3,590
Total	3,642	3,590	$ 3,404	$ 3,342
CRE [Member]
Individually evaluated for impairment	101	104
Collectively evaluated for impairment	76,296	71,953
Total	76,397	72,057
Collectively evaluated for impairment	894	833
Total	894	833	913	753
MF [Member]
Collectively evaluated for impairment	8,900	8,998
Total	8,900	8,998
Collectively evaluated for impairment	78	80
Total	78	80	39	60
C+I [Member]
Individually evaluated for impairment	25	28
Collectively evaluated for impairment	28,434	26,823
Total	28,459	26,851
Collectively evaluated for impairment	218	194
Total	218	194	206	267
ADL [Member]
Collectively evaluated for impairment	17,423	21,365
Total	17,423	21,365
Collectively evaluated for impairment	116	178
Total	116	178	296	174
RES [Member]
Individually evaluated for impairment	680	722
Collectively evaluated for impairment	234,593	233,477
Total	235,273	234,199
Collectively evaluated for impairment	2,188	2,139
Total	2,188	2,139	1,559	1,656
HELOC [Member]
Individually evaluated for impairment	115	115
Collectively evaluated for impairment	6,454	6,832
Total	6,569	6,947
Collectively evaluated for impairment	62	63
Total	62	63	67	78
CON [Member]
Collectively evaluated for impairment	4,988	4,574
Total	4,988	4,574
Collectively evaluated for impairment	86	75
Total	$ 86	75	50	52
Unallocated [Member]
Collectively evaluated for impairment		28
Total		$ 28	$ 274	$ 302