Investment Securities - Summary of Amortized Cost and Fair Value of Available for Sale and Held to Maturity Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Held to maturity amortized cost	$ 95,840	$ 100,841
Held to maturity fair value	84,713	90,030
Aaa [Member]
Debt Securities, Available-for-sale [Line Items]
Held to maturity amortized cost	11,261	11,382
Held to maturity fair value	9,179	9,473
Aa1/Aa2/Aa3 [Member]
Debt Securities, Available-for-sale [Line Items]
Held to maturity amortized cost	3,069	3,072
Held to maturity fair value	2,563	2,559
A1/A2/A3 [Member]
Debt Securities, Available-for-sale [Line Items]
Held to maturity amortized cost	4,774	4,770
Held to maturity fair value	3,466	3,543
Not rated [Member]
Debt Securities, Available-for-sale [Line Items]
Held to maturity amortized cost	76,736	81,617
Held to maturity fair value	$ 69,505	$ 74,455