Note 5 - Loans - Newly Restructured Loans and Types of Modifications (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Financing receivable modifications	$ 61	$ 1,058	$ 61	$ 1,178
Interest Rate Reduction and Extension of Maturity [Member]
Financing receivable modifications		1,058		1,058
Rate Reduction and Payment Deferral [Member]
Financing receivable modifications	61		61
Payment Deferral [Member]
Financing receivable modifications				120
Commercial Portfolio Segment [Member]
Financing receivable modifications		1,058		1,058
Commercial Portfolio Segment [Member] | Interest Rate Reduction and Extension of Maturity [Member]
Financing receivable modifications		1,058		1,058
Commercial Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Financing receivable modifications
Commercial Portfolio Segment [Member] | Payment Deferral [Member]
Financing receivable modifications
Residential Portfolio Segment [Member] | Individual Tax Identification Number Loan [Member] | Real Estate Loan [Member]
Financing receivable modifications	61		61	120
Residential Portfolio Segment [Member] | Interest Rate Reduction and Extension of Maturity [Member] | Individual Tax Identification Number Loan [Member] | Real Estate Loan [Member]
Financing receivable modifications
Residential Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member] | Individual Tax Identification Number Loan [Member] | Real Estate Loan [Member]
Financing receivable modifications	61		61
Residential Portfolio Segment [Member] | Payment Deferral [Member] | Individual Tax Identification Number Loan [Member] | Real Estate Loan [Member]
Financing receivable modifications				$ 120