Securities - Summary of Amortized Cost of Held-to Maturity Debt Securities Aggregated by Credit Quality Indicator (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Amortized Cost, Held to maturity	$ 216,899	$ 226,279
U.S. Treasury Securities [Member]
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Amortized Cost, Held to maturity	10,329	10,305
U.S. Treasury Securities [Member] | AAA / AA / A [Member]
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Amortized Cost, Held to maturity	10,329	10,305
Mortgage-Backed Securities of Government Agencies [Member]
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Amortized Cost, Held to maturity	204,036	213,425
Mortgage-Backed Securities of Government Agencies [Member] | AAA / AA / A [Member]
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Amortized Cost, Held to maturity	204,036	213,425
State and Political Subdivisions [Member]
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Amortized Cost, Held to maturity	2,534	2,549
State and Political Subdivisions [Member] | AAA / AA / A [Member]
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Amortized Cost, Held to maturity	$ 2,534	$ 2,549