Note 3 - Loans and Allowance for Loan Losses - Allowance Related to Troubled Debt Restructurings (Details) - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Related allowance	$ 412,000	$ 694,000
Commercial Portfolio Segment [Member]
Related allowance	361,000	642,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Related allowance	2,000	9,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Related allowance	13,000	28,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Related allowance	90,000	100,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Related allowance	157,000	247,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Related allowance	99,000	258,000
Retail Portfolio Segment [Member]
Related allowance	51,000	52,000
Retail Portfolio Segment [Member] | Home Equity and Other [Member]
Related allowance	47,000	48,000
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Related allowance	$ 4,000	$ 4,000