Significant Accounting Policies - Schedule of Impact of CECL Adoption (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Jan. 01, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses			$ 28,511	$ 27,773	$ 27,435	$ 26,641
Reserve for Unfunded Commitments	$ 3,400	$ 3,400
Total Reserve for Credit Losses	35,280		28,511
Decrease to Retained Earnings	176,644		156,492
Cumulative Effect, Period of Adoption, Adjustment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Decrease to Retained Earnings	(6,100)	6,100
ASU 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		34,475
Reserve for Unfunded Commitments		3,386
Total Reserve for Credit Losses		37,861
ASU 2016-13 [Member] | CECL Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		4,296
Reserve for Unfunded Commitments		3,386
Total Reserve for Credit Losses		7,682
Retained Earnings, Total Pre-tax Impact		(7,682)
Retained Earnings, Tax Effect		1,613
ASU 2016-13 [Member] | CECL Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Decrease to Retained Earnings		(6,069)
ASU 2016-13 [Member] | PCD Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		1,668
Total Reserve for Credit Losses	$ 1,668	1,668
Commercial and Agriculture [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses			3,011	2,729	2,790	2,600
Commercial and Agriculture [Member] | ASU 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		3,830
Commercial and Agriculture [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		429
Commercial and Agriculture [Member] | ASU 2016-13 [Member] | PCD Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		390
Commercial Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses			4,565	4,926	4,729	4,464
Commercial Real Estate Owner Occupied [Member] | ASU 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		5,819
Commercial Real Estate Owner Occupied [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		1,075
Commercial Real Estate Owner Occupied [Member] | ASU 2016-13 [Member] | PCD Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		179
Commercial Real Estate Non Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses			14,138	14,427	14,711	13,860
Commercial Real Estate Non Owner Occupied [Member] | ASU 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		11,291
Commercial Real Estate Non Owner Occupied [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		(2,847)
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses			3,145	3,036	2,859	2,597
Residential Real Estate [Member] | ASU 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		6,293
Residential Real Estate [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		2,762
Residential Real Estate [Member] | ASU 2016-13 [Member] | PCD Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		386
Real Estate Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses			2,293	2,013	1,969	1,810
Real Estate Construction [Member] | ASU 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		3,795
Real Estate Construction [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		1,502
Farm Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses			291	251	236	287
Farm Real Estate [Member] | ASU 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		263
Farm Real Estate [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		(28)
Lease Financing Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses			429
Lease Financing Receivables [Member] | ASU 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		2,807
Lease Financing Receivables [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		1,743
Lease Financing Receivables [Member] | ASU 2016-13 [Member] | PCD Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		635
Consumer and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses			98	142	130	176
Consumer and Other [Member] | ASU 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		377
Consumer and Other [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		201
Consumer and Other [Member] | ASU 2016-13 [Member] | PCD Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		78
Unallocated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses			$ 541	$ 249	$ 11	$ 847
Unallocated [Member] | ASU 2016-13 [Member] | CECL Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Credit Losses		$ (541)