Loans and Allowance for Loan Losses (Allowance For Loan Losses By Segment) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance	$ 4,411	$ 4,505	$ 4,505
Charge-Offs	(138)	(62)	(370)
Recoveries	52	502	901
(Recovery of) provision for loan losses	205	(527)	(625)
Ending Balance	4,530	4,418	4,411
Ending balance: Individually evaluated for impairment	326		458
Ending balance: collectively evaluated for impairment	4,204		3,953
Loans Ending Balance	582,033		569,238
Ending balance individually evaluated for impairment	6,714		11,426
Ending balance collectively evaluated for impairment	575,319		557,812
Construction and Farmland
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance	332	450	450
Charge-Offs	0		(19)
Recoveries	11		535
(Recovery of) provision for loan losses	19		(634)
Ending Balance	362		332
Ending balance: Individually evaluated for impairment	0		0
Ending balance: collectively evaluated for impairment	362		332
Loans Ending Balance	56,627		52,354
Ending balance individually evaluated for impairment	306		315
Ending balance collectively evaluated for impairment	56,321		52,039
Residential
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance	1,754	1,992	1,992
Charge-Offs	0		(55)
Recoveries	8		212
(Recovery of) provision for loan losses	(51)		(395)
Ending Balance	1,711		1,754
Ending balance: Individually evaluated for impairment	167		195
Ending balance: collectively evaluated for impairment	1,544		1,559
Loans Ending Balance	222,060		227,305
Ending balance individually evaluated for impairment	3,947		8,315
Ending balance collectively evaluated for impairment	218,113		218,990
Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance	1,627	1,522	1,522
Charge-Offs	0		(1)
Recoveries	2		65
(Recovery of) provision for loan losses	35		41
Ending Balance	1,664		1,627
Ending balance: Individually evaluated for impairment	58		59
Ending balance: collectively evaluated for impairment	1,606		1,568
Loans Ending Balance	245,909		239,915
Ending balance individually evaluated for impairment	1,877		1,904
Ending balance collectively evaluated for impairment	244,032		238,011
Commercial - Non Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance	570	235	235
Charge-Offs	(122)		(187)
Recoveries	20		44
(Recovery of) provision for loan losses	35		478
Ending Balance	503		570
Ending balance: Individually evaluated for impairment	92		195
Ending balance: collectively evaluated for impairment	411		375
Loans Ending Balance	38,498		37,427
Ending balance individually evaluated for impairment	574		858
Ending balance collectively evaluated for impairment	37,924		36,569
Consumer
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance	69	69	69
Charge-Offs	(1)		(59)
Recoveries	7		40
(Recovery of) provision for loan losses	(10)		19
Ending Balance	65		69
Ending balance: Individually evaluated for impairment	9		9
Ending balance: collectively evaluated for impairment	56		60
Loans Ending Balance	9,471		10,187
Ending balance individually evaluated for impairment	10		34
Ending balance collectively evaluated for impairment	9,461		10,153
All Other Loans
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance	29	22	22
Charge-Offs	(15)		(49)
Recoveries	4		5
(Recovery of) provision for loan losses	95		51
Ending Balance	113		29
Ending balance: Individually evaluated for impairment	0		0
Ending balance: collectively evaluated for impairment	113		29
Loans Ending Balance	9,468		2,050
Ending balance individually evaluated for impairment	0		0
Ending balance collectively evaluated for impairment	9,468		2,050
Unallocated
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance	30	$ 215	215
(Recovery of) provision for loan losses	82		(185)
Ending Balance	112		30
Ending balance: collectively evaluated for impairment	$ 112		$ 30

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

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- Definition

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

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- Definition

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

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- Definition

Amount of recovery of financing receivables doubtful of collection that were previously charged off.

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- Definition

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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No definition available.

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Amount of direct write-downs of financing receivables charged against the allowance.

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

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

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- Definition

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.

+ 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

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- Definition

Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

+ 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)(2)
-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 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 3: 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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