Note 4 - Loans and Related Allowance for Loan Loss - Loans Classified as TDRs (Details) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Number of contracts	0
Originated Loans [Member]
Number of contracts		1
Pre-modification outstanding recorded investment		$ 7
Nonperforming loans	$ 1,322	7	$ 1,335
Related allowance
Originated Loans [Member] \| Other Portfolio Segment [Member]
Number of contracts		1
Pre-modification outstanding recorded investment		$ 7
Nonperforming loans	4	7	4
Related allowance
Originated Loans [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Sector [Member]
Nonperforming loans	1,312		1,325
Acquired Loans [Member]
Number of contracts		2
Pre-modification outstanding recorded investment		$ 576
Nonperforming loans	2,117	584	2,352
Related allowance
Acquired Loans [Member] \| Residential Portfolio Segment [Member] \| Real Estate Sector [Member]
Number of contracts		1
Pre-modification outstanding recorded investment		$ 37
Nonperforming loans	1,289	45	1,299
Related allowance
Acquired Loans [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Sector [Member]
Number of contracts		1
Pre-modification outstanding recorded investment		$ 539
Nonperforming loans	$ 471	539	$ 660
Related allowance

The amount of reserve to cover probable credit losses related to financing receivables that were modified by troubled debt restructurings during the reporting period and were individually evaluated for impairment

No definition available.

+ Details

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

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- Definition

Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

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- Definition

Pre-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

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