Loans - Summary of Activities in Allowance for Credit Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Allowance for Loan Losses
Balance at beginning of year	$ 24,680	$ 24,634	$ 25,024	$ 20,313	$ 20,313
Provision for credit losses - loans	605	143	316	960	1,698
Charge Offs	(85)	(60)	(277)	(182)	(990)
Recoveries	70	193	207	255	439
Balance at ending of year	25,270	24,910	25,270	24,910	25,024
Consumer Real Estate [Member]
Allowance for Loan Losses
Balance at beginning of year	3,285	3,623	3,581	998	998
Provision for credit losses - loans	(82)	369	(372)	113	(326)
Charge Offs	(3)		(13)
Recoveries	1	6	5	13	35
Balance at ending of year	3,201	3,998	3,201	3,998	3,581
Agricultural Real Estate [Member]
Allowance for Loan Losses
Balance at beginning of year	1,171	209	312	349	349
Provision for credit losses - loans	(245)	(76)	614	(50)	24
Recoveries		104		104	105
Balance at ending of year	926	237	926	237	312
Agricultural [Member]
Allowance for Loan Losses
Balance at beginning of year	377	66	336	751	751
Provision for credit losses - loans	(92)	41	(51)	6	225
Recoveries					10
Balance at ending of year	285	107	285	107	336
Commercial Real Estate [Member]
Allowance for Loan Losses
Balance at beginning of year	15,953	16,088	17,400	11,924	11,924
Provision for credit losses - loans	365	590	(1,085)	1,251	1,967
Recoveries	1	3	4	5	8
Balance at ending of year	16,319	16,681	16,319	16,681	17,400
Commercial and Industrial [Member]
Allowance for Loan Losses
Balance at beginning of year	2,732	3,414	2,093	5,382	5,382
Provision for credit losses - loans	596	(653)	1,270	(462)	(643)
Charge Offs			(101)		(565)
Recoveries	39	6	105	12	84
Balance at ending of year	3,367	2,767	3,367	2,767	2,093
Consumer [Member]
Allowance for Loan Losses
Balance at beginning of year	1,162	1,234	1,302	909	909
Provision for credit losses - loans	63	(128)	(60)	102	451
Charge Offs	(82)	(60)	(163)	(182)	(425)
Recoveries	29	74	93	121	197
Balance at ending of year	$ 1,172	$ 1,120	$ 1,172	1,120	1,302
Cumulative Effect, Period of Adoption, Adjustment [Member]
Allowance for Loan Losses
Balance at beginning of year				$ 3,564	$ 3,564
Accounting Standards Update [Extensible Enumeration]				Accounting Standards Update 2016-13 [Member]	Accounting Standards Update 2016-13 [Member]
Cumulative Effect, Period of Adoption, Adjustment [Member] | Consumer Real Estate [Member]
Allowance for Loan Losses
Balance at beginning of year				$ 2,874	$ 2,874
Cumulative Effect, Period of Adoption, Adjustment [Member] | Agricultural Real Estate [Member]
Allowance for Loan Losses
Balance at beginning of year				(166)	(166)
Cumulative Effect, Period of Adoption, Adjustment [Member] | Agricultural [Member]
Allowance for Loan Losses
Balance at beginning of year				(650)	(650)
Cumulative Effect, Period of Adoption, Adjustment [Member] | Commercial Real Estate [Member]
Allowance for Loan Losses
Balance at beginning of year				3,501	3,501
Cumulative Effect, Period of Adoption, Adjustment [Member] | Commercial and Industrial [Member]
Allowance for Loan Losses
Balance at beginning of year				(2,165)	(2,165)
Cumulative Effect, Period of Adoption, Adjustment [Member] | Consumer [Member]
Allowance for Loan Losses
Balance at beginning of year				$ 170	$ 170