Note 7 - Loans and the Allowance for Loan Losses - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Loans	$ 1,528,469	$ 975,284
Pass [Member]
Loans	1,474,420	924,290
Special Mention [Member]
Loans	26,763	32,824
Substandard [Member]
Loans	15,595	5,635
Doubtful [Member]
Loans	11,691	12,535
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member]
Loans	211,054	143,535
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member] | Pass [Member]
Loans	209,027	141,128
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member] | Special Mention [Member]
Loans	718	1,953
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member] | Substandard [Member]
Loans	1,277	362
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member] | Doubtful [Member]
Loans	32	92
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member]
Loans	45,989	10,480
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member] | Pass [Member]
Loans	45,563	10,480
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member] | Special Mention [Member]
Loans	153	0
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member] | Substandard [Member]
Loans	161	0
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member] | Doubtful [Member]
Loans	112	0
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member]
Loans	518,660	337,699
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Pass [Member]
Loans	494,698	325,216
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Special Mention [Member]
Loans	14,421	4,861
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Substandard [Member]
Loans	3,510	1,687
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Doubtful [Member]
Loans	6,031	5,935
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member]
Loans	270,583	157,505
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member] | Pass [Member]
Loans	260,325	148,845
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member] | Special Mention [Member]
Loans	4,601	4,657
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member] | Substandard [Member]
Loans	2,929	1,574
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member] | Doubtful [Member]
Loans	2,728	2,429
Residential Portfolio Segment [Member] | Multi-family Residential [Member]
Loans	39,273	20,717
Residential Portfolio Segment [Member] | Multi-family Residential [Member] | Pass [Member]
Loans	39,237	20,677
Residential Portfolio Segment [Member] | Multi-family Residential [Member] | Special Mention [Member]
Loans	0	0
Residential Portfolio Segment [Member] | Multi-family Residential [Member] | Substandard [Member]
Loans	36	40
Residential Portfolio Segment [Member] | Multi-family Residential [Member] | Doubtful [Member]
Loans	0	0
Commercial Portfolio Segment [Member]
Loans	363,640	254,427
Commercial Portfolio Segment [Member] | Pass [Member]
Loans	347,839	228,157
Commercial Portfolio Segment [Member] | Special Mention [Member]
Loans	5,690	20,681
Commercial Portfolio Segment [Member] | Substandard [Member]
Loans	7,448	1,951
Commercial Portfolio Segment [Member] | Doubtful [Member]
Loans	2,663	3,638
Consumer Portfolio Segment [Member]
Loans	79,270	50,921
Consumer Portfolio Segment [Member] | Pass [Member]
Loans	77,731	49,787
Consumer Portfolio Segment [Member] | Special Mention [Member]
Loans	1,180	672
Consumer Portfolio Segment [Member] | Substandard [Member]
Loans	234	21
Consumer Portfolio Segment [Member] | Doubtful [Member]
Loans	$ 125	$ 441