Note 6 - Loans and the Allowance for Loan Losses - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Loans	$ 1,586,182	$ 1,528,469
Pass [Member]
Loans	1,532,943	1,474,420
Special Mention [Member]
Loans	24,289	26,763
Substandard [Member]
Loans	15,767	15,595
Doubtful [Member]
Loans	13,183	11,691
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member]
Loans	211,888	211,054
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member] | Pass [Member]
Loans	208,997	209,027
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member] | Special Mention [Member]
Loans	1,568	718
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member] | Substandard [Member]
Loans	1,214	1,277
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member] | Doubtful [Member]
Loans	109	32
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member]
Loans	44,066	45,989
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member] | Pass [Member]
Loans	43,697	45,563
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member] | Special Mention [Member]
Loans	152	153
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member] | Substandard [Member]
Loans	15	161
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member] | Doubtful [Member]
Loans	202	112
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member]
Loans	550,103	518,660
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Pass [Member]
Loans	526,600	494,698
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Special Mention [Member]
Loans	12,604	14,421
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Substandard [Member]
Loans	4,562	3,510
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Doubtful [Member]
Loans	6,337	6,031
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member]
Loans	275,610	270,583
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member] | Pass [Member]
Loans	264,981	260,325
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member] | Special Mention [Member]
Loans	4,956	4,601
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member] | Substandard [Member]
Loans	2,714	2,929
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member] | Doubtful [Member]
Loans	2,959	2,728
Residential Portfolio Segment [Member] | Multi-family Residential [Member]
Loans	39,548	39,273
Residential Portfolio Segment [Member] | Multi-family Residential [Member] | Pass [Member]
Loans	39,513	39,237
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	35	36
Residential Portfolio Segment [Member] | Multi-family Residential [Member] | Doubtful [Member]
Loans	0	0
Commercial Portfolio Segment [Member]
Loans	389,855	363,640
Commercial Portfolio Segment [Member] | Pass [Member]
Loans	375,412	347,839
Commercial Portfolio Segment [Member] | Special Mention [Member]
Loans	3,985	5,690
Commercial Portfolio Segment [Member] | Substandard [Member]
Loans	7,081	7,448
Commercial Portfolio Segment [Member] | Doubtful [Member]
Loans	3,377	2,663
Consumer Portfolio Segment [Member]
Loans	75,112	79,270
Consumer Portfolio Segment [Member] | Pass [Member]
Loans	73,743	77,731
Consumer Portfolio Segment [Member] | Special Mention [Member]
Loans	1,024	1,180
Consumer Portfolio Segment [Member] | Substandard [Member]
Loans	146	234
Consumer Portfolio Segment [Member] | Doubtful [Member]
Loans	$ 199	$ 125