Allowance for Credit Losses - Aging Analysis of Past Due Loans (Detail) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	$ 3,095,994	$ 3,081,230
Past Due 90 Days and Accruing	177	225
30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	730	7,154
60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	2,435	10,136
90 Days or Greater Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	3,786	7,298
Financial Asset, Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	6,951	24,588
Financial Asset, Not Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	3,089,043	3,056,642
Commercial and Agriculture [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	302,407	328,488
Past Due 90 Days and Accruing	85
Commercial and Agriculture [Member] \| 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	112	825
Commercial and Agriculture [Member] \| 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	48	114
Commercial and Agriculture [Member] \| 90 Days or Greater Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	429	1,374
Commercial and Agriculture [Member] \| Financial Asset, Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	589	2,313
Commercial and Agriculture [Member] \| Financial Asset, Not Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	301,818	326,175
Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	384,176	374,367
Past Due 90 Days and Accruing		225
Commercial Real Estate Owner Occupied [Member] \| 90 Days or Greater Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	7	225
Commercial Real Estate Owner Occupied [Member] \| Financial Asset, Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	7	225
Commercial Real Estate Owner Occupied [Member] \| Financial Asset, Not Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	384,169	374,142
Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	1,216,031	1,225,991
Commercial Real Estate Non Owner Occupied [Member] \| 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans		69
Commercial Real Estate Non Owner Occupied [Member] \| 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	654	8,000
Commercial Real Estate Non Owner Occupied [Member] \| 90 Days or Greater Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	484	2,514
Commercial Real Estate Non Owner Occupied [Member] \| Financial Asset, Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	1,138	10,583
Commercial Real Estate Non Owner Occupied [Member] \| Financial Asset, Not Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	1,214,893	1,215,408
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	842,362	763,869
Residential Real Estate [Member] \| 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	538	5,504
Residential Real Estate [Member] \| 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	1,391	1,634
Residential Real Estate [Member] \| 90 Days or Greater Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	2,000	2,273
Residential Real Estate [Member] \| Financial Asset, Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	3,929	9,411
Residential Real Estate [Member] \| Financial Asset, Not Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	838,433	754,458
Real Estate Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	278,163	305,992
Real Estate Construction [Member] \| Financial Asset, Not Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	278,163	305,992
Farm Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	23,713	23,035
Farm Real Estate [Member] \| 90 Days or Greater Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	400
Farm Real Estate [Member] \| Financial Asset, Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	400
Farm Real Estate [Member] \| Financial Asset, Not Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	23,313	23,035
Lease Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	38,960	46,900
Past Due 90 Days and Accruing	92
Lease Financing Receivable [Member] \| 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans		575
Lease Financing Receivable [Member] \| 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	327	351
Lease Financing Receivable [Member] \| 90 Days or Greater Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	449	909
Lease Financing Receivable [Member] \| Financial Asset, Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	776	1,835
Lease Financing Receivable [Member] \| Financial Asset, Not Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	38,184	45,065
Consumer and Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	10,182	12,588
Consumer and Other [Member] \| 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	80	181
Consumer and Other [Member] \| 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	15	37
Consumer and Other [Member] \| 90 Days or Greater Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	17	3
Consumer and Other [Member] \| Financial Asset, Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	112	221
Consumer and Other [Member] \| Financial Asset, Not Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	$ 10,070	$ 12,367