Note 3 - Loans and Allowance for Loan Losses - Loans Modified as Troubled Debt Restructurings (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)
Originated Loan [Member]
Number of Contracts	6	2	9	7
Pre- Modification Recorded Principal Balance	$ 15,630,000	$ 974,000	$ 16,019,000	$ 2,310,000
Post- Modification Recorded Principal Balance	$ 15,927,000	$ 1,079,000	$ 16,316,000	$ 2,392,000
Acquired Loan [Member]
Number of Contracts	5	6	11	11
Pre- Modification Recorded Principal Balance	$ 192,000	$ 137,000	$ 984,000	$ 241,000
Post- Modification Recorded Principal Balance	$ 193,000	$ 138,000	$ 974,000	$ 242,000
Commercial Portfolio Segment [Member] | Originated Loan [Member]
Number of Contracts	4	2	7	6
Pre- Modification Recorded Principal Balance	$ 15,607,000	$ 974,000	$ 15,996,000	$ 2,260,000
Post- Modification Recorded Principal Balance	$ 15,904,000	$ 1,079,000	$ 16,293,000	$ 2,342,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member]
Number of Contracts	3	2	6	4
Pre- Modification Recorded Principal Balance	$ 14,040,000	$ 974,000	$ 14,429,000	$ 1,068,000
Post- Modification Recorded Principal Balance	$ 14,337,000	$ 1,079,000	$ 14,726,000	$ 1,162,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Number of Contracts	0	0	0	0
Pre- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Post- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member]
Number of Contracts	1	0	1	2
Pre- Modification Recorded Principal Balance	$ 1,567,000	$ 0	$ 1,567,000	$ 1,192,000
Post- Modification Recorded Principal Balance	$ 1,567,000	$ 0	$ 1,567,000	$ 1,180,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Number of Contracts	0	0	0	0
Pre- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Post- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Number of Contracts	0	0	0	0
Pre- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Post- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member]
Number of Contracts	0	0	1	0
Pre- Modification Recorded Principal Balance	$ 0	$ 0	$ 690,000	$ 0
Post- Modification Recorded Principal Balance	$ 0	$ 0	$ 679,000	$ 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member]
Number of Contracts	0	0	0	0
Pre- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Post- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Number of Contracts	0	0	0	0
Pre- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Post- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member]
Number of Contracts	0	0	1	0
Pre- Modification Recorded Principal Balance	$ 0	$ 0	$ 690,000	$ 0
Post- Modification Recorded Principal Balance	$ 0	$ 0	$ 679,000	$ 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Number of Contracts	0	0	0	0
Pre- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Post- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Number of Contracts	0	0	0	0
Pre- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Post- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Retail Portfolio Segment [Member] | Originated Loan [Member]
Number of Contracts	2	0	2	1
Pre- Modification Recorded Principal Balance	$ 23,000	$ 0	$ 23,000	$ 50,000
Post- Modification Recorded Principal Balance	$ 23,000	$ 0	$ 23,000	$ 50,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | Home Equity and Other [Member]
Number of Contracts	2	0	2	1
Pre- Modification Recorded Principal Balance	$ 23,000	$ 0	$ 23,000	$ 50,000
Post- Modification Recorded Principal Balance	$ 23,000	$ 0	$ 23,000	$ 50,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | One to Four Family Mortgages [Member]
Number of Contracts	0	0	0	0
Pre- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Post- Modification Recorded Principal Balance	$ 0	$ 0	$ 0	$ 0
Retail Portfolio Segment [Member] | Acquired Loan [Member]
Number of Contracts	5	6	10	11
Pre- Modification Recorded Principal Balance	$ 192,000	$ 137,000	$ 294,000	$ 241,000
Post- Modification Recorded Principal Balance	$ 193,000	$ 138,000	$ 295,000	$ 242,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Home Equity and Other [Member]
Number of Contracts	2	5	6	10
Pre- Modification Recorded Principal Balance	$ 70,000	$ 113,000	$ 140,000	$ 217,000
Post- Modification Recorded Principal Balance	$ 71,000	$ 114,000	$ 141,000	$ 218,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | One to Four Family Mortgages [Member]
Number of Contracts	3	1	4	1
Pre- Modification Recorded Principal Balance	$ 122,000	$ 24,000	$ 154,000	$ 24,000
Post- Modification Recorded Principal Balance	$ 122,000	$ 24,000	$ 154,000	$ 24,000