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Note 8 - Loans and Related Allowance for Loan and Lease Losses - Additional Information on Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Average recorded investment	$ 15,529	$ 12,356
Interest income recognized	344	194
Commercial And Industrial [Member]
Average recorded investment	5,631	1,372
Interest income recognized	187	84
Real Estate Construction Porfolio Segment [Member]
Average recorded investment	283	810
Interest income recognized
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Average recorded investment	2,892	3,092
Interest income recognized	21	22
Real Estate Mortgage Portfolio Segment [Member] | Commercial Loans [Member]
Average recorded investment	6,719	7,077
Interest income recognized	136	88
Consumer Portfolio Segment [Member]
Average recorded investment	4	5
Interest income recognized

X

- Definition

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5258-111524

+ Details

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Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

+ Details

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- Details

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