Investment Securities - Amount of Securities in Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than twelve months, fair value	$ 24,517	$ 65,044
Debt securities, held-to-maturity, continuous unrealized loss position, less than 12 months, accumulated loss	(1,228)	(5,894)
Twelve months or longer, fair value	109,318	69,024
Debt securities, held-to-maturity, continuous unrealized loss position, 12 months or longer, accumulated loss	(18,446)	(14,765)
Total, fair value	133,835	134,068
Debt securities, held-to-maturity, unrealized loss position, accumulated loss	(19,674)	(20,659)
Debt Securities, Available-for-sale, Unrealized Gain (Loss) [Abstract]
Less than twelve months, fair value	61,628	130,888
Available-for-sale securities, continuous unrealized loss position, less than 12 months, accumulated loss	(2,067)	(13,908)
Twelve months or longer, fair value	211,816	135,922
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, accumulated loss	(38,660)	(28,537)
Total, fair value	273,444	266,810
Available-for-sale securities, continuous unrealized loss position, accumulated loss	(40,727)	(42,445)
Residential Mortgage-Backed Securities [Member]
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than twelve months, fair value	24,517	65,044
Debt securities, held-to-maturity, continuous unrealized loss position, less than 12 months, accumulated loss	(1,228)	(5,894)
Twelve months or longer, fair value	109,318	69,024
Debt securities, held-to-maturity, continuous unrealized loss position, 12 months or longer, accumulated loss	(18,446)	(14,765)
Total, fair value	133,835	134,068
Debt securities, held-to-maturity, unrealized loss position, accumulated loss	(19,674)	(20,659)
Debt Securities, Available-for-sale, Unrealized Gain (Loss) [Abstract]
Less than twelve months, fair value	61,628	128,831
Available-for-sale securities, continuous unrealized loss position, less than 12 months, accumulated loss	(2,067)	(13,843)
Twelve months or longer, fair value	208,143	133,902
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, accumulated loss	(38,358)	(28,300)
Total, fair value	269,771	262,733
Available-for-sale securities, continuous unrealized loss position, accumulated loss	(40,425)	(42,143)
State and Political Subdivisions [Member]
Debt Securities, Available-for-sale, Unrealized Gain (Loss) [Abstract]
Less than twelve months, fair value	0	1,255
Available-for-sale securities, continuous unrealized loss position, less than 12 months, accumulated loss	0	(42)
Twelve months or longer, fair value	1,254	0
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, accumulated loss	(45)	0
Total, fair value	1,254	1,255
Available-for-sale securities, continuous unrealized loss position, accumulated loss	(45)	(42)
Collateralized Mortgage Obligations [Member]
Debt Securities, Available-for-sale, Unrealized Gain (Loss) [Abstract]
Less than twelve months, fair value	0	302
Available-for-sale securities, continuous unrealized loss position, less than 12 months, accumulated loss	0	(22)
Twelve months or longer, fair value	2,139	2,020
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, accumulated loss	(256)	(237)
Total, fair value	2,139	2,322
Available-for-sale securities, continuous unrealized loss position, accumulated loss	(256)	(259)
Corporate Bonds [Member]
Debt Securities, Available-for-sale, Unrealized Gain (Loss) [Abstract]
Less than twelve months, fair value	0	500
Available-for-sale securities, continuous unrealized loss position, less than 12 months, accumulated loss	0	(1)
Twelve months or longer, fair value	280	0
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, accumulated loss	(1)	0
Total, fair value	280	500
Available-for-sale securities, continuous unrealized loss position, accumulated loss	$ (1)	$ (1)

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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