Investment Securities and Other Investments - Summary of Unrealized Losses (Detail) $ in Thousands	Sep. 30, 2024 USD ($) Security	Dec. 31, 2023 USD ($) Security
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Number of Securities \| Security	212	219
Available-for-sale Securities, Fair Value, Less Than 12 Months	$ 2,539	$ 15,785
Available-for-sale Securities, Unrealized Losses, Less Than 12 Months	(41)	(885)
Available-for-sale Securities, Fair Value, 12 Months or Greater	309,246	300,674
Available-for-sale Securities, Unrealized Losses, 12 months or Greater	(44,652)	(57,700)
Fair Value, Total	311,785	316,459
Unrealized Losses, Total	$ (44,693)	$ (58,585)
State and Municipal [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Number of Securities \| Security	64	65
Available-for-sale Securities, Fair Value, Less Than 12 Months	$ 330	$ 536
Available-for-sale Securities, Unrealized Losses, Less Than 12 Months	(1)	(9)
Available-for-sale Securities, Fair Value, 12 Months or Greater	41,953	41,118
Available-for-sale Securities, Unrealized Losses, 12 months or Greater	(5,766)	(7,348)
Fair Value, Total	42,283	41,654
Unrealized Losses, Total	$ (5,767)	$ (7,357)
U.S. Treasury and Agencies [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Number of Securities \| Security	29	29
Available-for-sale Securities, Fair Value, Less Than 12 Months	$ 0	$ 283
Available-for-sale Securities, Unrealized Losses, Less Than 12 Months	0	(1)
Available-for-sale Securities, Fair Value, 12 Months or Greater	71,452	68,399
Available-for-sale Securities, Unrealized Losses, 12 months or Greater	(7,975)	(10,984)
Fair Value, Total	71,452	68,682
Unrealized Losses, Total	$ (7,975)	$ (10,985)
Mortgage Backed Securities [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Number of Securities \| Security	79	86
Available-for-sale Securities, Fair Value, Less Than 12 Months		$ 7,497
Available-for-sale Securities, Unrealized Losses, Less Than 12 Months		(45)
Available-for-sale Securities, Fair Value, 12 Months or Greater	$ 165,434	169,474
Available-for-sale Securities, Unrealized Losses, 12 months or Greater	(27,434)	(35,199)
Fair Value, Total	165,434	176,971
Unrealized Losses, Total	$ (27,434)	$ (35,244)
Corporate Bonds [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Number of Securities \| Security	40	39
Available-for-sale Securities, Fair Value, Less Than 12 Months	$ 2,209	$ 7,469
Available-for-sale Securities, Unrealized Losses, Less Than 12 Months	(40)	(830)
Available-for-sale Securities, Fair Value, 12 Months or Greater	30,407	21,683
Available-for-sale Securities, Unrealized Losses, 12 months or Greater	(3,477)	(4,169)
Fair Value, Total	32,616	29,152
Unrealized Losses, Total	$ (3,517)	$ (4,999)

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