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Note 7 - Loans and Related Allowance for Loan and Lease Losses - Troubled Debt Restructurings Subsequently Defaulted (Details)	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Mar. 31, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017	Sep. 30, 2016 USD ($)
Number of contracts, subsequently defaulted	0	1		0
Recorded investment, subsequently defaulted		$ 33,000
Commercial And Industrial [Member]
Number of contracts, subsequently defaulted			1		2
Recorded investment, subsequently defaulted			$ 3,000		$ 273,000
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Number of contracts, subsequently defaulted			1
Recorded investment, subsequently defaulted			$ 58,000
Real Estate Construction Porfolio Segment [Member]
Number of contracts, subsequently defaulted					1
Recorded investment, subsequently defaulted					$ 58,000

X

- Definition

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524

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X

- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524

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- Details

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