Note 7 - Loans and the Allowance for Loan Losses - Past Due Loans Receivable (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Loans	$ 3,189,608,000	$ 2,991,355,000
Recorded investment over 90 days past due and still accruing	222,000	1,523,000
Financial Asset, 30 to 59 Days Past Due [Member]
Loans	2,352,000	9,694,000
Financial Asset, 60 to 89 Days Past Due [Member]
Loans	1,376,000	2,877,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	8,279,000	7,910,000
Financial Asset, Past Due [Member]
Loans	12,007,000	20,481,000
Financial Asset, Not Past Due [Member]
Loans	3,177,601,000	2,970,874,000
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member]
Loans	548,528,000	403,065,000
Recorded investment over 90 days past due and still accruing	0	72,000
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans	632,000	874,000
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans	16,000	75,000
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	488,000	972,000
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member] | Financial Asset, Past Due [Member]
Loans	1,136,000	1,921,000
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member] | Financial Asset, Not Past Due [Member]
Loans	547,392,000	401,144,000
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member]
Loans	87,463,000	55,883,000
Recorded investment over 90 days past due and still accruing	0	0
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans	83,000	0
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans	0	11,000
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	0	289,000
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member] | Financial Asset, Past Due [Member]
Loans	83,000	300,000
Commercial Real Estate Portfolio Segment [Member] | Farmland [Member] | Financial Asset, Not Past Due [Member]
Loans	87,380,000	55,583,000
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member]
Loans	1,144,426,000	971,603,000
Recorded investment over 90 days past due and still accruing	0	315,000
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans	222,000	2,651,000
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans	627,000	1,049,000
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	1,767,000	2,514,000
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Financial Asset, Past Due [Member]
Loans	2,616,000	6,214,000
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Financial Asset, Not Past Due [Member]
Loans	1,141,810,000	965,389,000
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member]
Loans	467,699,000	468,650,000
Recorded investment over 90 days past due and still accruing	107,000	603,000
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans	917,000	3,162,000
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans	534,000	1,160,000
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	1,496,000	1,927,000
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member] | Financial Asset, Past Due [Member]
Loans	2,947,000	6,249,000
Residential Portfolio Segment [Member] | Real Estate Residential One- to Four-Family [Member] | Financial Asset, Not Past Due [Member]
Loans	464,752,000	462,401,000
Residential Portfolio Segment [Member] | Multi-family Residential [Member]
Loans	97,508,000	95,707,000
Recorded investment over 90 days past due and still accruing	0	0
Residential Portfolio Segment [Member] | Multi-family Residential [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans	0	0
Residential Portfolio Segment [Member] | Multi-family Residential [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans	0	0
Residential Portfolio Segment [Member] | Multi-family Residential [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	0	0
Residential Portfolio Segment [Member] | Multi-family Residential [Member] | Financial Asset, Past Due [Member]
Loans	0	0
Residential Portfolio Segment [Member] | Multi-family Residential [Member] | Financial Asset, Not Past Due [Member]
Loans	97,508,000	95,707,000
Commercial Portfolio Segment [Member]
Loans	721,385,000	886,325,000
Recorded investment over 90 days past due and still accruing	97,000	511,000
Commercial Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans	106,000	2,618,000
Commercial Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans	55,000	549,000
Commercial Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	4,257,000	1,925,000
Commercial Portfolio Segment [Member] | Financial Asset, Past Due [Member]
Loans	4,418,000	5,092,000
Commercial Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Loans	716,967,000	881,233,000
Consumer Portfolio Segment [Member]
Loans	122,599,000	110,122,000
Recorded investment over 90 days past due and still accruing	18,000	22,000
Consumer Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans	392,000	389,000
Consumer Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans	144,000	33,000
Consumer Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	271,000	283,000
Consumer Portfolio Segment [Member] | Financial Asset, Past Due [Member]
Loans	807,000	705,000
Consumer Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Loans	$ 121,792,000	$ 109,417,000