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Note 4 - Loans and Related Allowance of Loan and Lease Losses - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Individually evaluated for impairment				$ 1,567	$ 527
Collectively evaluated for impairment				5,623	6,071
Total ending allowance balance	$ 7,190	$ 6,598	$ 6,385	7,190	6,598
ALLL balance, period start	6,598	6,385
Charge-offs	(1,154)	(743)
Recoveries	701	386
Provision for Loan, Lease, and Other Losses	1,045	570	315
ALLL balance, period end	7,190	6,598	6,385
Commercial And Industrial [Member]
Individually evaluated for impairment				694	90
Collectively evaluated for impairment				305	358
Total ending allowance balance	999	448	867	999	448
ALLL balance, period start	448	867
Charge-offs	(536)	(237)
Recoveries	234	90
Provision for Loan, Lease, and Other Losses	853	(272)
ALLL balance, period end	999	448	867
Real Estate Construction Porfolio Segment [Member]
Individually evaluated for impairment
Collectively evaluated for impairment				313	172
Total ending allowance balance	313	172	276	313	172
ALLL balance, period start	172	276
Charge-offs
Recoveries	34
Provision for Loan, Lease, and Other Losses	107	(104)
ALLL balance, period end	313	172	276
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Individually evaluated for impairment				140	251
Collectively evaluated for impairment				1,620	2,567
Total ending allowance balance	1,760	2,818	3,139	1,760	2,818
ALLL balance, period start	2,818	3,139
Charge-offs	(117)	(414)
Recoveries	241	141
Provision for Loan, Lease, and Other Losses	(1,182)	(48)
ALLL balance, period end	1,760	2,818	3,139
Real Estate Mortgage Portfolio Segment [Member] | Commercial Loans [Member]
Individually evaluated for impairment				733	186
Collectively evaluated for impairment				3,303	2,949
Total ending allowance balance	4,036	3,135	2,078	4,036	3,135
ALLL balance, period start	3,135	2,078
Charge-offs	(39)	(70)
Recoveries	111	140
Provision for Loan, Lease, and Other Losses	829	987
ALLL balance, period end	4,036	3,135	2,078
Consumer Portfolio Segment [Member]
Individually evaluated for impairment
Collectively evaluated for impairment				82	25
Total ending allowance balance	82	25	25	$ 82	$ 25
ALLL balance, period start	25	25
Charge-offs	(462)	(22)
Recoveries	81	15
Provision for Loan, Lease, and Other Losses	438	7
ALLL balance, period end	$ 82	$ 25	$ 25

X

- Definition

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

+ 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)(4)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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X

- 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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X

- Definition

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

+ 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 (g)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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X

- Definition

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

+ 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 (g)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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X

- Definition

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.

+ 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 (g)
-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 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

Reference 3: 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

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 6.L.1)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74567-122707

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

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X

- 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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