Loans - Analysis of Allowance for Credit Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance	$ 17,847	$ 15,477	$ 17,283	$ 14,313	$ 14,313
Charge Offs	(117)	(38)	(211)	(1,051)	(1,332)
Recoveries	142	59	185	125	458
Provision (Credit)	1,628	641	2,208	2,341	3,444
Other Non-interest expense related to unfunded	91	93	126	504
Ending Balance	19,591	16,232	19,591	16,232	17,283
Ending balance: individually evaluated for impairment	2,419	1,156	2,419	1,156	2,184
Ending balance: collectively evaluated for impairment	17,172	15,076	17,172	15,076	15,099
Ending balance: loans acquired with deteriorated credit quality	0	0	0	0	37
FINANCING RECEIVABLES:
Ending balance	2,034,818	1,458,423	2,034,818	1,458,423	1,857,419
Ending balance: individually evaluated for impairment	10,669	12,039	10,669	12,039	11,939
Ending balance: collectively evaluated for impairment	2,023,141	1,444,645	2,023,141	1,444,645	1,844,031
Ending balance: loans acquired with deteriorated credit quality	1,008	1,739	1,008	1,739	1,449
Consumer Real Estate [Member]
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance	892	624	857	633	633
Recoveries	4	3	9	6
Provision (Credit)	43	22	73	10
Ending Balance	939	649	939	649	857
Ending balance: collectively evaluated for impairment	939	649	939	649	857
Ending balance: loans acquired with deteriorated credit quality	0	0	0	0	37
FINANCING RECEIVABLES:
Ending balance	410,468	194,574	410,468	194,574	395,805
Ending balance: individually evaluated for impairment	657	770	657	770	604
Ending balance: collectively evaluated for impairment	409,318	193,741	409,318	193,741	394,489
Ending balance: loans acquired with deteriorated credit quality	493	63	493	63	712
Agricultural Real Estate [Member]
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance	606	1,386	1,040	958	958
Provision (Credit)	(260)	(169)	(694)	259
Ending Balance	346	1,217	346	1,217	1,040
Ending balance: individually evaluated for impairment		914		914	691
Ending balance: collectively evaluated for impairment	346	303	346	303	349
Ending balance: loans acquired with deteriorated credit quality	0	0	0	0	0
FINANCING RECEIVABLES:
Ending balance	199,650	189,426	199,650	189,426	198,033
Ending balance: individually evaluated for impairment	2,414	6,522	2,414	6,522	6,725
Ending balance: collectively evaluated for impairment	197,039	181,923	197,039	181,923	191,107
Ending balance: loans acquired with deteriorated credit quality	197	981	197	981	201
Agricultural [Member]
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance	844	616	709	701	701
Charge Offs				(142)
Recoveries		6		6
Provision (Credit)	(90)	98	45	155
Ending Balance	754	720	754	720	709
Ending balance: individually evaluated for impairment		117		117	1
Ending balance: collectively evaluated for impairment	754	603	754	603	708
Ending balance: loans acquired with deteriorated credit quality	0	0	0	0	0
FINANCING RECEIVABLES:
Ending balance	127,340	100,905	127,340	100,905	118,504
Ending balance: individually evaluated for impairment	1,296	248	1,296	248	20
Ending balance: collectively evaluated for impairment	126,044	100,657	126,044	100,657	118,484
Commercial Real Estate [Member]
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance	9,573	7,668	9,130	7,415	7,415
Recoveries	3	3	5	5
Provision (Credit)	851	1,160	1,292	1,411
Ending Balance	10,427	8,831	10,427	8,831	9,130
Ending balance: individually evaluated for impairment		125		125	664
Ending balance: collectively evaluated for impairment	10,427	8,706	10,427	8,706	8,466
Ending balance: loans acquired with deteriorated credit quality	0	0	0	0	0
FINANCING RECEIVABLES:
Ending balance	977,588	689,728	977,588	689,728	847,110
Ending balance: individually evaluated for impairment	4,133	3,246	4,133	3,246	3,561
Ending balance: collectively evaluated for impairment	973,258	686,172	973,258	686,172	843,299
Ending balance: loans acquired with deteriorated credit quality	197	310	197	310	250
Commercial and Industrial [Member]
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance	4,066	2,608	3,847	3,346	3,346
Charge Offs			(6)	(809)
Recoveries	65	5	74	10
Provision (Credit)	1,234	224	1,450	290
Ending Balance	5,365	2,837	5,365	2,837	3,847
Ending balance: individually evaluated for impairment	2,419		2,419		825
Ending balance: collectively evaluated for impairment	2,946	2,837	2,946	2,837	3,022
Ending balance: loans acquired with deteriorated credit quality	0	0	0	0	0
FINANCING RECEIVABLES:
Ending balance	264,124	227,256	264,124	227,256	240,138
Ending balance: individually evaluated for impairment	2,149	1,236	2,149	1,236	1,003
Ending balance: collectively evaluated for impairment	261,854	225,635	261,854	225,635	238,849
Ending balance: loans acquired with deteriorated credit quality	121	385	121	385	286
Consumer [Member]
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance	623	595	625	606	606
Charge Offs	(117)	(38)	(205)	(100)
Recoveries	70	42	97	98
Provision (Credit)	(9)	14	50	9
Ending Balance	567	613	567	613	625
Ending balance: individually evaluated for impairment					3
Ending balance: collectively evaluated for impairment	567	613	567	613	622
Ending balance: loans acquired with deteriorated credit quality	0	0	0	0	0
FINANCING RECEIVABLES:
Ending balance	55,648	56,534	55,648	56,534	57,829
Ending balance: individually evaluated for impairment	20	17	20	17	26
Ending balance: collectively evaluated for impairment	55,628	56,517	55,628	56,517	57,803
Unallocated [Member]
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance	167	928	34	13	13
Provision (Credit)	(141)	(708)	(8)	207
Ending Balance	26	220	26	220	34
Ending balance: collectively evaluated for impairment	26	220	26	220	34
Ending balance: loans acquired with deteriorated credit quality	0	0	0	0	0
Unfunded Loan Commitment & Letters of Credit [Member]
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance	1,076	1,052	1,041	641	641
Other Non-interest expense related to unfunded	91	93	126	504
Ending Balance	1,167	1,145	1,167	1,145	1,041
Ending balance: collectively evaluated for impairment	1,167	1,145	1,167	1,145	1,041
Ending balance: loans acquired with deteriorated credit quality	$ 0	$ 0	$ 0	$ 0	$ 0