Loans and Allowance for Credit Losses on Loans - Analysis Of Past Due Loans By Portfolio Segment Including Non-Accrual Loans Without ACL (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Total Past Due	$ 437,991	$ 430,031
Non-Accrual Loans		141
60-89 Days Past Due [Member]
Total Past Due		131
Greater than 90 Days [Member]
Total Past Due		14
Total Past Due
Total Past Due		145
Current
Total Past Due	437,991	429,886
CRE [Member]
Total Past Due	85,696	86,566
CRE [Member] | Current
Total Past Due	85,696	86,566
MF [Member]
Total Past Due	5,824	7,582
MF [Member] | Current
Total Past Due	5,824	7,582
C+I [Member]
Total Past Due	24,096	25,511
C+I [Member] | Current
Total Past Due	24,096	25,511
ADL [Member]
Total Past Due	13,599	17,520
ADL [Member] | Current
Total Past Due	13,599	17,520
RES [Member]
Total Past Due	279,832	268,943
Non-Accrual Loans		127
RES [Member] | 60-89 Days Past Due [Member]
Total Past Due		131
RES [Member] | Total Past Due
Total Past Due		131
RES [Member] | Current
Total Past Due	279,832	268,812
HELOC [Member]
Total Past Due	16,678	14,093
Non-Accrual Loans		14
HELOC [Member] | Greater than 90 Days [Member]
Total Past Due		14
HELOC [Member] | Total Past Due
Total Past Due		14
HELOC [Member] | Current
Total Past Due	16,678	14,079
CON [Member]
Total Past Due	12,266	9,816
CON [Member] | Current
Total Past Due	$ 12,266	$ 9,816