Note 9 - Fair Value Measurement - Assets and Liabilities Measured at Fair Value On a Non-recurring Basis (Details) - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Fair Value Disclosure Nonrecurring
Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Fair Value Disclosure Nonrecurring
Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Fair Value Disclosure Nonrecurring	451,000		1,214,000
Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Impaired Loans [Member]
Assets Fair Value Disclosure Nonrecurring	451,000		1,214,000
Asset Impairment Charges	(83,000)
Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Other Real Estate [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Fair Value Disclosure Nonrecurring
Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Other Real Estate [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Fair Value Disclosure Nonrecurring
Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Other Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Fair Value Disclosure Nonrecurring	1,000,000		156,000
Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Other Real Estate [Member]
Assets Fair Value Disclosure Nonrecurring	1,000,000		156,000
Asset Impairment Charges	(9,000)	(127,000)
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Fair Value Disclosure Nonrecurring
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Fair Value Disclosure Nonrecurring
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Fair Value Disclosure Nonrecurring	22,000		30,000
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Impaired Loans [Member]
Assets Fair Value Disclosure Nonrecurring	22,000		30,000
Asset Impairment Charges	(1,000)	(16,000)
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Other Real Estate [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Fair Value Disclosure Nonrecurring
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Other Real Estate [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Fair Value Disclosure Nonrecurring
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Other Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Fair Value Disclosure Nonrecurring	1,517,000		1,516,000
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Other Real Estate [Member]
Assets Fair Value Disclosure Nonrecurring	1,517,000		1,516,000
Asset Impairment Charges		114,000
Commercial Portfolio Segment [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Fair Value Disclosure Nonrecurring
Commercial Portfolio Segment [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Fair Value Disclosure Nonrecurring
Commercial Portfolio Segment [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Fair Value Disclosure Nonrecurring
Commercial Portfolio Segment [Member] | Impaired Loans [Member]
Assets Fair Value Disclosure Nonrecurring
Asset Impairment Charges		(13,000)
Commercial Portfolio Segment [Member] | Other Real Estate [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Fair Value Disclosure Nonrecurring
Commercial Portfolio Segment [Member] | Other Real Estate [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Fair Value Disclosure Nonrecurring
Commercial Portfolio Segment [Member] | Other Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Fair Value Disclosure Nonrecurring
Commercial Portfolio Segment [Member] | Other Real Estate [Member]
Assets Fair Value Disclosure Nonrecurring
Asset Impairment Charges		(39,000)
Residential Portfolio Segment [Member] | Equity Lines of Credit [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Fair Value Disclosure Nonrecurring
Residential Portfolio Segment [Member] | Equity Lines of Credit [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Fair Value Disclosure Nonrecurring
Residential Portfolio Segment [Member] | Equity Lines of Credit [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Fair Value Disclosure Nonrecurring	83,000		83,000
Residential Portfolio Segment [Member] | Equity Lines of Credit [Member] | Impaired Loans [Member]
Assets Fair Value Disclosure Nonrecurring	83,000		83,000
Asset Impairment Charges	4,000	4,000
Residential Portfolio Segment [Member] | Equity Lines of Credit [Member] | Other Real Estate [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Fair Value Disclosure Nonrecurring
Residential Portfolio Segment [Member] | Equity Lines of Credit [Member] | Other Real Estate [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Fair Value Disclosure Nonrecurring
Residential Portfolio Segment [Member] | Equity Lines of Credit [Member] | Other Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Fair Value Disclosure Nonrecurring			84,000
Residential Portfolio Segment [Member] | Equity Lines of Credit [Member] | Other Real Estate [Member]
Assets Fair Value Disclosure Nonrecurring			84,000
Asset Impairment Charges		(27,000)
Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Fair Value Disclosure Nonrecurring
Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Fair Value Disclosure Nonrecurring
Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Fair Value Disclosure Nonrecurring	556,000		1,327,000
Impaired Loans [Member]
Assets Fair Value Disclosure Nonrecurring	556,000		1,327,000
Asset Impairment Charges	(80,000)	(25,000)
Other Real Estate [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Fair Value Disclosure Nonrecurring
Other Real Estate [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Fair Value Disclosure Nonrecurring
Other Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Fair Value Disclosure Nonrecurring	2,517,000		1,756,000
Other Real Estate [Member]
Assets Fair Value Disclosure Nonrecurring	2,517,000		1,756,000
Asset Impairment Charges	(9,000)	(79,000)
Fair Value, Inputs, Level 1 [Member]
Assets Fair Value Disclosure Nonrecurring
Fair Value, Inputs, Level 2 [Member]
Assets Fair Value Disclosure Nonrecurring
Fair Value, Inputs, Level 3 [Member]
Assets Fair Value Disclosure Nonrecurring	3,073,000		3,083,000
Assets Fair Value Disclosure Nonrecurring	3,073,000		$ 3,083,000
Asset Impairment Charges	$ (89,000)	$ (104,000)