Allowance for Credit Losses - Changes in the Allowance for Credit Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	$ 37,160	$ 28,511	$ 28,511
Charge-offs	(651)	(175)
Recoveries	298	47
Provision	2,042	620
Ending Balance	38,849	34,196	37,160
ASU 2016-13 [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance		897	897
ASU 2016-13 [Member] | CECL Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance		4,296	4,296
Commercial and Agriculture [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	7,587	3,011	3,011
Charge-offs	(212)	(140)
Recoveries	152	6
Provision	210	10
Ending Balance	7,737	3,316	7,587
Commercial and Agriculture [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance		429	429
Commercial Real Estate Owner Occupied [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	4,723	4,565	4,565
Recoveries	3
Provision	(74)	74
Ending Balance	4,652	5,733	4,723
Commercial Real Estate Owner Occupied [Member] | ASU 2016-13 [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance		19	19
Commercial Real Estate Owner Occupied [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance		1,075	1,075
Commercial Real Estate Non Owner Occupied [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	12,056	14,138	14,138
Charge-offs	(174)
Recoveries	5	7
Provision	1,081	462
Ending Balance	12,968	11,760	12,056
Commercial Real Estate Non Owner Occupied [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance		(2,847)	(2,847)
Residential Real Estate [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	8,489	3,145	3,145
Charge-offs	(13)	(10)
Recoveries	120	22
Provision	478	(151)
Ending Balance	9,074	5,934	8,489
Residential Real Estate [Member] | ASU 2016-13 [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance		166	166
Residential Real Estate [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance		2,762	2,762
Real Estate Construction [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	3,388	2,293	2,293
Recoveries	4	4
Provision	41	121
Ending Balance	3,433	3,920	3,388
Real Estate Construction [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance		1,502	1,502
Farm Real Estate [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	260	291	291
Provision	60	6
Ending Balance	320	269	260
Farm Real Estate [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance		(28)	(28)
Lease Financing Receivables [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	297	429	429
Charge-offs	(226)
Provision	288	100
Ending Balance	359	2,907	297
Lease Financing Receivables [Member] | ASU 2016-13 [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance		635	635
Lease Financing Receivables [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance		1,743	1,743
Consumer and Other [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	341	98	98
Charge-offs	(26)	(25)
Recoveries	14	8
Provision	(23)	(5)
Ending Balance	306	354	341
Consumer and Other [Member] | ASU 2016-13 [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance		77	77
Consumer and Other [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance		201	201
Unallocated [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	19	541	541
Provision	(19)	3
Ending Balance	$ 0	3	19
Unallocated [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance		$ (541)	$ (541)