Loans - Information About Loans And The ALL By Portfolio Segment Are Summarized (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Individually evaluated for impairment	$ 969	$ 1,001
Collectively evaluated for impairment	374,022	366,436
Total	374,991	367,437
Collectively evaluated for impairment	3,590	3,342
Total	3,590	3,342	$ 2,875
CRE [Member]
Individually evaluated for impairment	104	117
Collectively evaluated for impairment	71,953	66,049
Total	72,057	66,166
Collectively evaluated for impairment	833	753
Total	833	753	781
MF [Member]
Collectively evaluated for impairment	8,998	6,619
Total	8,998	6,619
Collectively evaluated for impairment	80	60
Total	80	60	23
C+I [Member]
Individually evaluated for impairment	28	822
Collectively evaluated for impairment	26,823	44,440
Total	26,851	45,262
Collectively evaluated for impairment	194	267
Total	194	267	350
ADL [Member]
Collectively evaluated for impairment	21,365	23,145
Total	21,365	23,145
Collectively evaluated for impairment	178	174
Total	178	174	145
RES [Member]
Individually evaluated for impairment	722	62
Collectively evaluated for impairment	233,477	213,656
Total	234,199	213,718
Collectively evaluated for impairment	2,139	1,656
Total	2,139	1,656	1,503
HELOC [Member]
Individually evaluated for impairment	115
Collectively evaluated for impairment	6,832	9,583
Total	6,947	9,583
Collectively evaluated for impairment	63	78
Total	63	78	52
CON [Member]
Collectively evaluated for impairment	4,574	2,944
Total	4,574	2,944
Collectively evaluated for impairment	75	52
Total	75	52	18
Unallocated [Member]
Collectively evaluated for impairment	28	302
Total	$ 28	$ 302	$ 3