Note 4 - Loans and Allowance for Loan Losses - Allowance Related to Troubled Debt Restructurings (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Related allowance	$ 694,000	$ 1,108,000
Commercial Portfolio Segment [Member]
Related allowance	642,000	1,088,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Related allowance	9,000	221,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Related allowance	28,000	186,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Related allowance	100,000	115,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Related allowance	247,000	201,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Related allowance	258,000	365,000
Retail Portfolio Segment [Member]
Related allowance	52,000	20,000
Retail Portfolio Segment [Member] | Home Equity and Other [Member]
Related allowance	48,000	14,000
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Related allowance	$ 4,000	$ 6,000