Derivatives and Hedging Activities - Summary of Balance Sheet Related to Cumulative Basis Adjustment for Fair Value Hedges (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Derivatives Fair Value [Line Items]
Carrying Amount of Hedged Assets/(Liabilities)	$ 60,966	$ 60,758
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets/(Liabilities)	966	758
Securities Available-for-sale, at Fair Value [Member]
Derivatives Fair Value [Line Items]
Carrying Amount of Hedged Assets/(Liabilities)	10,178	10,126
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets/(Liabilities)	178	126
Loans [Member]
Derivatives Fair Value [Line Items]
Carrying Amount of Hedged Assets/(Liabilities)	50,788	50,632
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets/(Liabilities)	$ 788	$ 632