Note 15 - Commitments and Contingent Liabilities - Off Balance Sheet Commitments to Extend Credit (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Off balance sheet commitments to extend credit	$ 1,082,091	$ 834,604
Commercial and Industrial Loans [Member]
Off balance sheet commitments to extend credit	384,038	309,920
Construction and Development [Member]
Off balance sheet commitments to extend credit	251,984	179,364
Home Equity Loans [Member]
Off balance sheet commitments to extend credit	151,800	147,907
Credit Cards [Member]
Off balance sheet commitments to extend credit	25,606	20,003
Overdrafts [Member]
Off balance sheet commitments to extend credit	22,083	21,751
Letters of Credit [Member]
Off balance sheet commitments to extend credit	22,827	20,891
Other Off Balance Sheet Commitments [Member]
Off balance sheet commitments to extend credit	43,910	33,369
Future Loan Commitments [Member]
Off balance sheet commitments to extend credit	$ 179,843	$ 101,399