Allowance For Credit Losses [Abstract]

No definition available.

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- Definition

Financing receivable allowance for credit losses acquired with deteriorated credit quality ending period.

+ References

No definition available.

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- Definition

Financing Receivables [Abstract]

+ References

No definition available.

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- Definition

Other non interest Income expense (recovery) related to unfunded.

+ References

No definition available.

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- Definition

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

+ References

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- Definition

Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(d))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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- Definition

A valuation allowance for financing receivables that are expected to be uncollectible.

+ References

+ Details

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- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

+ Details

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- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

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- Definition

The balance of financing receivables that were collectively evaluated for impairment.

+ References

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- Definition

The balance of financing receivables that were individually evaluated for impairment.

+ References

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- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524

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- Definition

Net amount of the investment in a contractual right to receive money on demand or on fixed or determinable dates that is recognized as an asset in the creditor's statement of financial position. Examples include, but are not limited to, credit card receivables, notes receivable and receivables relating to lessor's rights to payments from leases other than operating leases that have been recorded as assets. Excludes trade accounts receivable with contractual maturity of one year or less and arose from the sale of goods or services.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.3)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Amount of expense related to estimated loss from loan and lease transactions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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Loans - Analysis of Allowance for Credit Losses (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance				$ 7,001				$ 6,265	$ 7,001	$ 6,265
Charge Offs									(288)	(550)	$ (1,030)
Recoveries									150	156	557
Provision (Credit)	$ 25	$ 99	$ 25	73	$ 197	$ 308	$ 339	277	222	1,121	625
Other Non-interest expense related to unfunded									10	9
Ending Balance	7,095				7,001				7,095	7,001	6,265
Ending balance: individually evaluated for impairment	106				135				106	135
Ending balance: collectively evaluated for impairment	6,989				6,866				6,989	6,866
Ending balance: loans acquired with deteriorated credit quality					1					1
FINANCING RECEIVABLES:
Ending balance	823,024				758,094				823,024	758,094
Ending balance: individually evaluated for impairment	1,745				1,852				1,745	1,852
Ending balance: collectively evaluated for impairment	821,279				756,242				821,279	756,242
Agricultural Real Estate [Member]
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance				241				211	241	211
Provision (Credit)									3	30
Ending Balance	244				241				244	241	211
Ending balance: collectively evaluated for impairment	244				241				244	241
FINANCING RECEIVABLES:
Ending balance	64,044				62,336				64,044	62,336
Ending balance: individually evaluated for impairment	101				132				101	132
Ending balance: collectively evaluated for impairment	63,943				62,204				63,943	62,204
Agricultural [Member]
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance				616				582	616	582
Charge Offs										(21)
Recoveries									8	10
Provision (Credit)									43	45
Ending Balance	667				616				667	616	582
Ending balance: collectively evaluated for impairment	667				616				667	616
FINANCING RECEIVABLES:
Ending balance	95,238				84,692				95,238	84,692
Ending balance: collectively evaluated for impairment	95,238				84,692				95,238	84,692
Commercial And Industrial and Industrial Development Bonds [Member]
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance				1,318				1,229	1,318	1,229
Charge Offs										(20)
Recoveries									12	11
Provision (Credit)									216	98
Ending Balance	1,546				1,318				1,546	1,318	1,229
Ending balance: individually evaluated for impairment	39				35				39	35
Ending balance: collectively evaluated for impairment	1,507				1,283				1,507	1,283
FINANCING RECEIVABLES:
Ending balance	132,787				115,093				132,787	115,093
Ending balance: individually evaluated for impairment	444				116				444	116
Ending balance: collectively evaluated for impairment	132,343				114,977				132,343	114,977
Unfunded Loan Commitment & Letters of Credit [Member]
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance				217				208	217	208
Other Non-interest expense related to unfunded									10	9
Ending Balance	227				217				227	217	208
Ending balance: collectively evaluated for impairment	227				217				227	217
Receivables Acquired with Deteriorated Credit Quality [Member]
FINANCING RECEIVABLES:
Ending balance: loans acquired with deteriorated credit quality	122				200				122	200
Consumer Real Estate [Member]
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance				316				338	316	338
Charge Offs									(4)	(106)
Recoveries									13	28
Provision (Credit)									18	56
Ending Balance	343				316				343	316	338
Ending balance: individually evaluated for impairment	21				34				21	34
Ending balance: collectively evaluated for impairment	322				282				322	282
Ending balance: loans acquired with deteriorated credit quality					1					1
FINANCING RECEIVABLES:
Ending balance	83,200				85,873				83,200	85,873
Ending balance: individually evaluated for impairment	575				1,103				575	1,103
Ending balance: collectively evaluated for impairment	82,625				84,770				82,625	84,770
Consumer Real Estate [Member] \| Receivables Acquired with Deteriorated Credit Quality [Member]
FINANCING RECEIVABLES:
Ending balance: loans acquired with deteriorated credit quality	122				200				122	200
Commercial Real Estate [Member]
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance				3,250				2,516	3,250	2,516
Charge Offs									(21)	(93)
Recoveries									15	20
Provision (Credit)									(95)	807
Ending Balance	3,149				3,250				3,149	3,250	2,516
Ending balance: individually evaluated for impairment	46				66				46	66
Ending balance: collectively evaluated for impairment	3,103				3,184				3,103	3,184
FINANCING RECEIVABLES:
Ending balance	409,953				376,887				409,953	376,887
Ending balance: individually evaluated for impairment	625				501				625	501
Ending balance: collectively evaluated for impairment	409,328				376,386				409,328	376,386
Consumer [Member]
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance				394				337	394	337
Charge Offs									(263)	(310)
Recoveries									102	87
Provision (Credit)									208	280
Ending Balance	441				394				441	394	337
Ending balance: collectively evaluated for impairment	441				394				441	394
FINANCING RECEIVABLES:
Ending balance	37,802				33,213				37,802	33,213
Ending balance: collectively evaluated for impairment	37,802				33,213				37,802	33,213
Unallocated [Member]
ALLOWANCE FOR CREDIT LOSSES:
Beginning balance				$ 649				$ 844	649	844
Provision (Credit)									(171)	(195)
Ending Balance	478				649				478	649	$ 844
Ending balance: collectively evaluated for impairment	$ 478				$ 649				$ 478	$ 649