Note 4 - Loans and Allowance for Loan Losses - Nonperforming Loans (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Originated Loan [Member]
Loans past due 90 days or more still accruing interest	$ 0	$ 0
Originated Loan [Member] | Commercial Portfolio Segment [Member]
Loans past due 90 days or more still accruing interest	0	0
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans past due 90 days or more still accruing interest	0	0
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans past due 90 days or more still accruing interest	0	0
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans past due 90 days or more still accruing interest	0	0
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans past due 90 days or more still accruing interest	0	0
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans past due 90 days or more still accruing interest	0	0
Originated Loan [Member] | Retail Portfolio Segment [Member]
Loans past due 90 days or more still accruing interest	0	0
Originated Loan [Member] | Retail Portfolio Segment [Member] | Home Equity and Other [Member]
Loans past due 90 days or more still accruing interest	0	0
Originated Loan [Member] | Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Loans past due 90 days or more still accruing interest	0	0
Acquired Loan [Member]
Loans past due 90 days or more still accruing interest	0	0
Acquired Loan [Member] | Commercial Portfolio Segment [Member]
Loans past due 90 days or more still accruing interest	0	0
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans past due 90 days or more still accruing interest	0	0
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans past due 90 days or more still accruing interest	0	0
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans past due 90 days or more still accruing interest	0	0
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans past due 90 days or more still accruing interest	0	0
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans past due 90 days or more still accruing interest	0	0
Acquired Loan [Member] | Retail Portfolio Segment [Member]
Loans past due 90 days or more still accruing interest	0	0
Acquired Loan [Member] | Retail Portfolio Segment [Member] | Home Equity and Other [Member]
Loans past due 90 days or more still accruing interest	0	0
Acquired Loan [Member] | Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Loans past due 90 days or more still accruing interest	0	0
Nonperforming Financial Instruments [Member]
Total nonperforming loans	5,939,000	5,444,000
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member]
Total nonperforming loans	3,181,000	2,646,000
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Total nonperforming loans	2,296,000	458,000
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Total nonperforming loans	95,000	155,000
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Total nonperforming loans	285,000	1,797,000
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Total nonperforming loans	488,000	79,000
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Total nonperforming loans	17,000	157,000
Nonperforming Financial Instruments [Member] | Retail Portfolio Segment [Member]
Total nonperforming loans	2,758,000	2,798,000
Nonperforming Financial Instruments [Member] | Retail Portfolio Segment [Member] | Home Equity and Other [Member]
Total nonperforming loans	496,000	771,000
Nonperforming Financial Instruments [Member] | Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Total nonperforming loans	2,262,000	2,027,000
Nonperforming Financial Instruments [Member] | Originated Loan [Member]
Loans past due 90 days or more still accruing interest	0	0
Nonaccrual loans	3,328,000	1,954,000
Total nonperforming loans	3,328,000	1,954,000
Nonperforming Financial Instruments [Member] | Acquired Loan [Member]
Loans past due 90 days or more still accruing interest	0	5,000
Nonaccrual loans	2,611,000	3,485,000
Total nonperforming loans	$ 2,611,000	$ 3,490,000