Note 4 - Loans and Allowance for Loan Losses - Loans Modified as Troubled Debt Restructurings (Details)	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Originated Loan [Member]
Number of Contracts	18	10
Pre- Modification Recorded Principal Balance	$ 2,512,000	$ 2,022,000
Post- Modification Recorded Principal Balance	$ 3,288,000	$ 2,047,000
Acquired Loan [Member]
Number of Contracts	11	20
Pre- Modification Recorded Principal Balance	$ 1,067,000	$ 2,262,000
Post- Modification Recorded Principal Balance	$ 1,068,000	$ 2,262,000
Commercial Portfolio Segment [Member] | Originated Loan [Member]
Number of Contracts	14	9
Pre- Modification Recorded Principal Balance	$ 2,239,000	$ 1,876,000
Post- Modification Recorded Principal Balance	$ 3,008,000	$ 1,901,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member]
Number of Contracts	8	9
Pre- Modification Recorded Principal Balance	$ 1,445,000	$ 1,876,000
Post- Modification Recorded Principal Balance	$ 2,103,000	$ 1,901,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Number of Contracts	0	0
Pre- Modification Recorded Principal Balance	$ 0	$ 0
Post- Modification Recorded Principal Balance	$ 0	$ 0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member]
Number of Contracts	1	0
Pre- Modification Recorded Principal Balance	$ 167,000	$ 0
Post- Modification Recorded Principal Balance	$ 167,000	$ 0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Number of Contracts	1	0
Pre- Modification Recorded Principal Balance	$ 462,000	$ 0
Post- Modification Recorded Principal Balance	$ 462,000	$ 0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Number of Contracts	4	0
Pre- Modification Recorded Principal Balance	$ 165,000	$ 0
Post- Modification Recorded Principal Balance	$ 276,000	$ 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member]
Number of Contracts	6	19
Pre- Modification Recorded Principal Balance	$ 955,000	$ 2,119,000
Post- Modification Recorded Principal Balance	$ 955,000	$ 2,119,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member]
Number of Contracts	0	3
Pre- Modification Recorded Principal Balance	$ 0	$ 624,000
Post- Modification Recorded Principal Balance	$ 0	$ 624,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Number of Contracts	0	0
Pre- Modification Recorded Principal Balance	$ 0	$ 0
Post- Modification Recorded Principal Balance	$ 0	$ 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member]
Number of Contracts	3	7
Pre- Modification Recorded Principal Balance	$ 739,000	$ 494,000
Post- Modification Recorded Principal Balance	$ 739,000	$ 494,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Number of Contracts	2	5
Pre- Modification Recorded Principal Balance	$ 209,000	$ 714,000
Post- Modification Recorded Principal Balance	$ 209,000	$ 714,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Number of Contracts	1	4
Pre- Modification Recorded Principal Balance	$ 7,000	$ 287,000
Post- Modification Recorded Principal Balance	$ 7,000	$ 287,000
Retail Portfolio Segment [Member] | Originated Loan [Member]
Number of Contracts	4	1
Pre- Modification Recorded Principal Balance	$ 273,000	$ 146,000
Post- Modification Recorded Principal Balance	$ 280,000	$ 146,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | Home Equity and Other [Member]
Number of Contracts	3	1
Pre- Modification Recorded Principal Balance	$ 240,000	$ 146,000
Post- Modification Recorded Principal Balance	$ 240,000	$ 146,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | One to Four Family Mortgages [Member]
Number of Contracts	1	0
Pre- Modification Recorded Principal Balance	$ 33,000	$ 0
Post- Modification Recorded Principal Balance	$ 40,000	$ 0
Retail Portfolio Segment [Member] | Acquired Loan [Member]
Number of Contracts	5	1
Pre- Modification Recorded Principal Balance	$ 112,000	$ 143,000
Post- Modification Recorded Principal Balance	$ 113,000	$ 143,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Home Equity and Other [Member]
Number of Contracts	4	0
Pre- Modification Recorded Principal Balance	$ 93,000	$ 0
Post- Modification Recorded Principal Balance	$ 94,000	$ 0
Retail Portfolio Segment [Member] | Acquired Loan [Member] | One to Four Family Mortgages [Member]
Number of Contracts	1	1
Pre- Modification Recorded Principal Balance	$ 19,000	$ 143,000
Post- Modification Recorded Principal Balance	$ 19,000	$ 143,000