Note 19 - Concentrations of Credit - (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Loans and Leases Receivable, Net of Deferred Income	$ 975,284	$ 810,951
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member]
Loans and Leases Receivable, Net of Deferred Income	$ 337,699	$ 298,057
Commercial Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Loan Secured by Real Estate [Member] | Credit Concentration Risk [Member]
Concentration Risk, Percentage	34.60%	36.80%
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member]
Loans and Leases Receivable, Net of Deferred Income	$ 143,535	$ 94,426
Commercial Real Estate Portfolio Segment [Member] | Construction and Land [Member] | Loan Secured by Real Estate [Member] | Credit Concentration Risk [Member]
Concentration Risk, Percentage	14.70%	11.60%