Note 6 - Loans and Allowance for Loan Losses - Carrying Amount of Impaired Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Real Estate [Member] | Construction, Land Development and Other Land Loans [Member]
Impaired loans with no related allowance recorded, Carrying Amount
Impaired loans with no related allowance recorded, Unpaid Principal Balance
Impaired loans with an allowance recorded, Carrying Amount	1,361	1,445
Impaired loans with an allowance recorded, Unpaid Principal Balance	1,361	1,445
Impaired loans with an allowance recorded, Related Allowances	305	95
Total impaired loans, Carrying Amount	1,361	1,445
Total impaired loans, Unpaid Principal Balance	1,361	1,445
Total impaired loans, Related Allowance	305	95
Total impaired loans, Carrying Amount	1,361	1,445
Total impaired loans, Unpaid Principal Balance	1,361	1,445
Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member]
Impaired loans with no related allowance recorded, Carrying Amount		54
Impaired loans with no related allowance recorded, Unpaid Principal Balance		54
Impaired loans with an allowance recorded, Carrying Amount	195	198
Impaired loans with an allowance recorded, Unpaid Principal Balance	195	198
Impaired loans with an allowance recorded, Related Allowances	5	5
Total impaired loans, Carrying Amount	195	252
Total impaired loans, Unpaid Principal Balance	195	252
Total impaired loans, Related Allowance	5	5
Total impaired loans, Carrying Amount	195	252
Total impaired loans, Unpaid Principal Balance	195	252
Real Estate [Member] | Secured by Multi-family Residential Properties [Member]
Impaired loans with no related allowance recorded, Carrying Amount
Impaired loans with no related allowance recorded, Unpaid Principal Balance
Impaired loans with an allowance recorded, Carrying Amount
Impaired loans with an allowance recorded, Unpaid Principal Balance
Impaired loans with an allowance recorded, Related Allowances
Total impaired loans, Carrying Amount
Total impaired loans, Unpaid Principal Balance
Total impaired loans, Related Allowance
Total impaired loans, Carrying Amount
Total impaired loans, Unpaid Principal Balance
Real Estate [Member] | Secured by Non-farm, Non-residential Properties [Member]
Impaired loans with no related allowance recorded, Carrying Amount
Impaired loans with no related allowance recorded, Unpaid Principal Balance
Impaired loans with an allowance recorded, Carrying Amount	551	573
Impaired loans with an allowance recorded, Unpaid Principal Balance	551	573
Impaired loans with an allowance recorded, Related Allowances	108	130
Total impaired loans, Carrying Amount	551	573
Total impaired loans, Unpaid Principal Balance	551	573
Total impaired loans, Related Allowance	108	130
Total impaired loans, Carrying Amount	551	573
Total impaired loans, Unpaid Principal Balance	551	573
Commercial and Industrial Loans [Member]
Impaired loans with no related allowance recorded, Carrying Amount
Impaired loans with no related allowance recorded, Unpaid Principal Balance
Impaired loans with an allowance recorded, Carrying Amount		444
Impaired loans with an allowance recorded, Unpaid Principal Balance		444
Impaired loans with an allowance recorded, Related Allowances		80
Total impaired loans, Carrying Amount		444
Total impaired loans, Unpaid Principal Balance		444
Total impaired loans, Related Allowance		80
Total impaired loans, Carrying Amount		444
Total impaired loans, Unpaid Principal Balance		444
Impaired loans with no related allowance recorded, Carrying Amount		54
Impaired loans with no related allowance recorded, Unpaid Principal Balance		54
Impaired loans with an allowance recorded, Carrying Amount	2,107	2,660
Impaired loans with an allowance recorded, Unpaid Principal Balance	2,107	2,660
Impaired loans with an allowance recorded, Related Allowances	418	310
Total impaired loans, Carrying Amount	2,107	2,714
Total impaired loans, Unpaid Principal Balance	2,107	2,714
Total impaired loans, Related Allowance	418	310
Total impaired loans, Carrying Amount	2,107	2,714
Total impaired loans, Unpaid Principal Balance	$ 2,107	$ 2,714