Note 5 - Loans - Newly Restructured Loans and Types of Modifications (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing receivable modifications	$ 2,447	$ 1,505	$ 3,677
Interest Rate Reduction and Extension of Maturity [Member]
Financing receivable modifications	1,049	39	3,431
Contractual Interest Rate Reduction [Member]
Financing receivable modifications		115	207
Principal Forgiveness [Member]
Financing receivable modifications	81
Rate Reduction and Payment Deferral [Member]
Financing receivable modifications		264	39
Extended Maturity [Member]
Financing receivable modifications	1,120
Payment Deferral [Member]
Financing receivable modifications	197	1,087
Commercial Portfolio Segment [Member]
Financing receivable modifications	2,025	747	3,396
Commercial Portfolio Segment [Member] | Interest Rate Reduction and Extension of Maturity [Member]
Financing receivable modifications	905	39	3,396
Commercial Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]
Financing receivable modifications
Commercial Portfolio Segment [Member] | Principal Forgiveness [Member]
Financing receivable modifications
Commercial Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Financing receivable modifications
Commercial Portfolio Segment [Member] | Extended Maturity [Member]
Financing receivable modifications	1,120
Commercial Portfolio Segment [Member] | Payment Deferral [Member]
Financing receivable modifications		708
Residential Portfolio Segment [Member] | Individual Tax Identification Number Loan [Member] | Real Estate Loan [Member]
Financing receivable modifications	278	758	246
Residential Portfolio Segment [Member] | Mortgage Receivable [Member] | Real Estate Loan [Member]
Financing receivable modifications	144
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] | Interest Rate Reduction and Extension of Maturity [Member] | Mortgage Receivable [Member] | Real Estate Loan [Member]
Financing receivable modifications	144
Residential Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member] | Individual Tax Identification Number Loan [Member] | Real Estate Loan [Member]
Financing receivable modifications		115	207
Residential Portfolio Segment [Member] | Principal Forgiveness [Member] | Individual Tax Identification Number Loan [Member] | Real Estate Loan [Member]
Financing receivable modifications	81
Residential Portfolio Segment [Member] | Principal Forgiveness [Member] | Mortgage Receivable [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		264	39
Residential Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member] | Mortgage Receivable [Member] | Real Estate Loan [Member]
Financing receivable modifications
Residential Portfolio Segment [Member] | Extended Maturity [Member] | Individual Tax Identification Number Loan [Member] | Real Estate Loan [Member]
Financing receivable modifications
Residential Portfolio Segment [Member] | Extended Maturity [Member] | Mortgage Receivable [Member] | Real Estate Loan [Member]
Financing receivable modifications
Residential Portfolio Segment [Member] | Payment Deferral [Member] | Individual Tax Identification Number Loan [Member] | Real Estate Loan [Member]
Financing receivable modifications	197	$ 379
Residential Portfolio Segment [Member] | Payment Deferral [Member] | Mortgage Receivable [Member] | Real Estate Loan [Member]
Financing receivable modifications
Consumer Portfolio Segment [Member]
Financing receivable modifications			35
Consumer Portfolio Segment [Member] | Interest Rate Reduction and Extension of Maturity [Member]
Financing receivable modifications			35
Consumer Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]
Financing receivable modifications
Consumer Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Financing receivable modifications
Consumer Portfolio Segment [Member] | Extended Maturity [Member]
Financing receivable modifications
Consumer Portfolio Segment [Member] | Payment Deferral [Member]
Financing receivable modifications