Investments - Summary of Gross Unrealized Losses and Fair Value of Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Schedule of Investments [Line Items]
Total, Available-for-sale securities, Less Than 12 Months, Fair Value	$ 338,365	$ 24,282
Total, Available-for-sale securities, Less Than 12 Months, Unrecognized Loss	(2,879)	(787)
Total, Available-for-sale securities, 12 Months or More, Fair Value	577,802	606,838
Total, Available-for-sale securities, 12 Months or More, Unrecognized Loss	(82,580)	(80,735)
Total, Available-for-sale securities, Fair Value	916,167	631,120
Total, Available-for-sale securities, Unrecognized Loss	(85,459)	(81,522)
Total, Held-to-maturity securities, Less Than 12 Months, Fair Value	1,061
Total, Held-to-maturity securities, Less Than 12 Months, Unrecognized Loss	(25)
Total, Held-to-maturity securities, Fair Value	1,061
Total, Held-to-maturity securities, Unrecognized Loss	(25)
U.S. Government Sponsored Entities [Member]
Schedule of Investments [Line Items]
Total, Available-for-sale securities, Less Than 12 Months, Fair Value	42,820
Total, Available-for-sale securities, Less Than 12 Months, Unrecognized Loss	(292)
Total, Available-for-sale securities, 12 Months or More, Fair Value	32,312	33,087
Total, Available-for-sale securities, 12 Months or More, Unrecognized Loss	(6,384)	(6,016)
Total, Available-for-sale securities, Fair Value	75,132	33,087
Total, Available-for-sale securities, Unrecognized Loss	(6,676)	(6,016)
U.S. Treasury securities [Member]
Schedule of Investments [Line Items]
Total, Available-for-sale securities, Less Than 12 Months, Fair Value	65,470	0
Total, Available-for-sale securities, Less Than 12 Months, Unrecognized Loss	(229)
Total, Available-for-sale securities, 12 Months or More, Fair Value	19,591	19,413
Total, Available-for-sale securities, 12 Months or More, Unrecognized Loss	(512)	(771)
Total, Available-for-sale securities, Fair Value	85,061	19,413
Total, Available-for-sale securities, Unrecognized Loss	(741)	(771)
Government-Sponsored Residential Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Total, Available-for-sale securities, Less Than 12 Months, Fair Value	207,375	7,799
Total, Available-for-sale securities, Less Than 12 Months, Unrecognized Loss	(1,436)	(5)
Total, Available-for-sale securities, 12 Months or More, Fair Value	287,668	306,858
Total, Available-for-sale securities, 12 Months or More, Unrecognized Loss	(37,685)	(35,398)
Total, Available-for-sale securities, Fair Value	495,043	314,657
Total, Available-for-sale securities, Unrecognized Loss	(39,121)	(35,403)
Total, Held-to-maturity securities, Less Than 12 Months, Fair Value	1,061
Total, Held-to-maturity securities, Less Than 12 Months, Unrecognized Loss	(25)
Total, Held-to-maturity securities, Fair Value	1,061
Total, Held-to-maturity securities, Unrecognized Loss	(25)
Private Label Residential Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Total, Available-for-sale securities, 12 Months or More, Fair Value	129,065	137,841
Total, Available-for-sale securities, 12 Months or More, Unrecognized Loss	(23,096)	(23,333)
Total, Available-for-sale securities, Fair Value	129,065	137,841
Total, Available-for-sale securities, Unrecognized Loss	(23,096)	(23,333)
Corporate [Member]
Schedule of Investments [Line Items]
Total, Available-for-sale securities, Less Than 12 Months, Fair Value	4,646
Total, Available-for-sale securities, Less Than 12 Months, Unrecognized Loss	(54)
Total, Available-for-sale securities, 12 Months or More, Fair Value	46,743	49,683
Total, Available-for-sale securities, 12 Months or More, Unrecognized Loss	(5,170)	(7,039)
Total, Available-for-sale securities, Fair Value	51,389	49,683
Total, Available-for-sale securities, Unrecognized Loss	(5,224)	(7,039)
Small Business Administration Loan Pools [Member]
Schedule of Investments [Line Items]
Total, Available-for-sale securities, Less Than 12 Months, Fair Value	4,462	5,097
Total, Available-for-sale securities, Less Than 12 Months, Unrecognized Loss	(2)	(14)
Total, Available-for-sale securities, 12 Months or More, Fair Value	2,411	2,630
Total, Available-for-sale securities, 12 Months or More, Unrecognized Loss	(328)	(325)
Total, Available-for-sale securities, Fair Value	6,873	7,727
Total, Available-for-sale securities, Unrecognized Loss	(330)	(339)
State and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Total, Available-for-sale securities, Less Than 12 Months, Fair Value	13,592	11,386
Total, Available-for-sale securities, Less Than 12 Months, Unrecognized Loss	(866)	(768)
Total, Available-for-sale securities, 12 Months or More, Fair Value	60,012	57,326
Total, Available-for-sale securities, 12 Months or More, Unrecognized Loss	(9,405)	(7,853)
Total, Available-for-sale securities, Fair Value	73,604	68,712
Total, Available-for-sale securities, Unrecognized Loss	$ (10,271)	$ (8,621)