Note 4 - Loans and Related Allowance for Loan and Lease Losses - Past Due Financing Receivables (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Loans, current balance	$ 915,131	$ 605,703
Loans, past due	8,082	3,437
Loans, total	923,213	609,140
Financing Receivables, 30 to 59 Days Past Due [Member]
Loans, past due	5,501	2,018
Financing Receivables, 60 to 89 Days Past Due [Member]
Loans, past due	257	219
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans, past due	2,324	1,200
Commercial And Industrial [Member]
Loans, current balance	99,633	60,407
Loans, past due	1,713	223
Loans, total	101,346	60,630
Commercial And Industrial [Member] \| Financing Receivables, 30 to 59 Days Past Due [Member]
Loans, past due	1,607	17
Commercial And Industrial [Member] \| Financing Receivables, 60 to 89 Days Past Due [Member]
Loans, past due	29	2
Commercial And Industrial [Member] \| Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans, past due	77	204
Real Estate Construction Porfolio Segment [Member]
Loans, current balance	47,017	23,709
Loans, past due	0	0
Loans, total	47,017	23,709
Real Estate Construction Porfolio Segment [Member] \| Financing Receivables, 30 to 59 Days Past Due [Member]
Loans, past due	0	0
Real Estate Construction Porfolio Segment [Member] \| Financing Receivables, 60 to 89 Days Past Due [Member]
Loans, past due	0	0
Real Estate Construction Porfolio Segment [Member] \| Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans, past due	0	0
Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member]
Loans, current balance	314,866	268,041
Loans, past due	3,291	2,789
Loans, total	318,157	270,830
Real Estate Mortgage Portfolio Segment [Member] \| Commercial Loans [Member]
Loans, current balance	434,879	249,081
Loans, past due	3,068	409
Loans, total	437,947	249,490
Real Estate Mortgage Portfolio Segment [Member] \| Financing Receivables, 30 to 59 Days Past Due [Member] \| Residential Loan [Member]
Loans, past due	1,977	1,909
Real Estate Mortgage Portfolio Segment [Member] \| Financing Receivables, 30 to 59 Days Past Due [Member] \| Commercial Loans [Member]
Loans, past due	1,907	92
Real Estate Mortgage Portfolio Segment [Member] \| Financing Receivables, 60 to 89 Days Past Due [Member] \| Residential Loan [Member]
Loans, past due	227	207
Real Estate Mortgage Portfolio Segment [Member] \| Financing Receivables, 60 to 89 Days Past Due [Member] \| Commercial Loans [Member]
Loans, past due	1
Real Estate Mortgage Portfolio Segment [Member] \| Financing Receivables, Equal to Greater than 90 Days Past Due [Member] \| Residential Loan [Member]
Loans, past due	1,087	673
Real Estate Mortgage Portfolio Segment [Member] \| Financing Receivables, Equal to Greater than 90 Days Past Due [Member] \| Commercial Loans [Member]
Loans, past due	1,160	317
Consumer Portfolio Segment [Member]
Loans, current balance	18,736	4,465
Loans, past due	10	16
Loans, total	18,746	4,481
Consumer Portfolio Segment [Member] \| Financing Receivables, 30 to 59 Days Past Due [Member]
Loans, past due	10
Consumer Portfolio Segment [Member] \| Financing Receivables, 60 to 89 Days Past Due [Member]
Loans, past due		10
Consumer Portfolio Segment [Member] \| Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans, past due		$ 6

Financing receivables that are current.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953401-111524

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- Definition

Recorded Investment in financing receivables that are past due at the balance sheet date.

+ 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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