Loans and Allowance for Loan Losses, Activity in Allowance for Loan Losses by Portfolio Segment (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Dec. 31, 2018
Activity in allowance for loan losses [Roll Forward]
Balance, beginning of period	$ 7,832	$ 7,654
Charge-offs	(4)	(55)
Recoveries	7	0
Net recoveries (charge-offs)	3	(55)
Provision (credit) for loan losses	0	100
Balance, end of period	7,835	7,699
Allowance Balance [Abstract]
Ending balance, individually evaluated for impairment			$ 35	$ 46
Ending balance, Collectively evaluated for impairment			7,800	7,786
Total	7,835	7,654	7,835	7,832
Gross Loans [Abstract]
Ending balance, individually evaluated for impairment			11,036	9,077
Ending balance, Collectively evaluated for impairment			577,124	592,825
Total			588,160	601,902
Construction & Development [Member]
Activity in allowance for loan losses [Roll Forward]
Balance, beginning of period	1,136	1,407
Charge-offs	0	0
Recoveries	0	0
Net recoveries (charge-offs)	0	0
Provision (credit) for loan losses	154	58
Balance, end of period	1,290	1,465
Allowance Balance [Abstract]
Ending balance, individually evaluated for impairment			0	0
Ending balance, Collectively evaluated for impairment			1,290	1,136
Total	1,136	1,407	1,290	1,136
Gross Loans [Abstract]
Ending balance, individually evaluated for impairment			0	0
Ending balance, Collectively evaluated for impairment			96,810	87,267
Total			96,810	87,267
1-4 Family Commercial [Member]
Activity in allowance for loan losses [Roll Forward]
Balance, beginning of period	433	431
Charge-offs	0	0
Recoveries	0	0
Net recoveries (charge-offs)	0	0
Provision (credit) for loan losses	19	66
Balance, end of period	452	497
Allowance Balance [Abstract]
Ending balance, individually evaluated for impairment			3	0
Ending balance, Collectively evaluated for impairment			449	433
Total	433	431	452	433
Gross Loans [Abstract]
Ending balance, individually evaluated for impairment			114	115
Ending balance, Collectively evaluated for impairment			33,829	33,163
Total			33,943	33,278
Commercial Real Estate - Other [Member]
Activity in allowance for loan losses [Roll Forward]
Balance, beginning of period	2,035	1,865
Charge-offs	0
Recoveries	0	0
Provision (credit) for loan losses	52	(309)
Balance, end of period	2,087	1,556
Allowance Balance [Abstract]
Ending balance, individually evaluated for impairment			32	32
Ending balance, Collectively evaluated for impairment			2,055	2,003
Total	2,035	1,865	2,087	2,035
Gross Loans [Abstract]
Ending balance, individually evaluated for impairment			1,944	484
Ending balance, Collectively evaluated for impairment			154,720	155,912
Total			156,664	156,396
Commercial & Industrial [Member]
Activity in allowance for loan losses [Roll Forward]
Balance, beginning of period	3,231	2,779
Charge-offs	(4)	(55)
Recoveries	7	0
Net recoveries (charge-offs)	3	(55)
Provision (credit) for loan losses	(166)	384
Balance, end of period	3,068	3,108
Allowance Balance [Abstract]
Ending balance, individually evaluated for impairment			0	14
Ending balance, Collectively evaluated for impairment			3,068	3,217
Total	3,231	2,779	3,068	3,231
Gross Loans [Abstract]
Ending balance, individually evaluated for impairment			5,675	7,381
Ending balance, Collectively evaluated for impairment			224,651	241,013
Total			230,326	248,394
Agricultural [Member]
Activity in allowance for loan losses [Roll Forward]
Balance, beginning of period	818	1,015
Charge-offs	0	0
Recoveries	0	0
Net recoveries (charge-offs)	0	0
Provision (credit) for loan losses	(58)	(143)
Balance, end of period	760	872
Allowance Balance [Abstract]
Ending balance, individually evaluated for impairment			0	0
Ending balance, Collectively evaluated for impairment			760	818
Total	818	1,015	760	818
Gross Loans [Abstract]
Ending balance, individually evaluated for impairment			3,014	1,097
Ending balance, Collectively evaluated for impairment			54,007	61,747
Total			57,021	62,844
Consumer [Member]
Activity in allowance for loan losses [Roll Forward]
Balance, beginning of period	179	157
Charge-offs	0	0
Recoveries	0	0
Net recoveries (charge-offs)	0	0
Provision (credit) for loan losses	(1)	44
Balance, end of period	178	201
Allowance Balance [Abstract]
Ending balance, individually evaluated for impairment			0	0
Ending balance, Collectively evaluated for impairment			178	179
Total	$ 179	$ 157	178	179
Gross Loans [Abstract]
Ending balance, individually evaluated for impairment			289	0
Ending balance, Collectively evaluated for impairment			13,107	13,723
Total			$ 13,396	$ 13,723

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

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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

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Amount, after recoveries, of loans and leases that have been written-off.

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

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

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

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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

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

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