Note 11 - Commitments and Contingent Liabilities - Off Balance Sheet Commitments to Extend Credit (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Off balance sheet commitments to extend credit	$ 1,672,725	$ 1,390,772
Commercial and Industrial Loans [Member]
Off balance sheet commitments to extend credit	666,520	555,077
Construction and Development [Member]
Off balance sheet commitments to extend credit	258,933	266,550
Home Equity Loans [Member]
Off balance sheet commitments to extend credit	234,903	175,132
Credit Cards [Member]
Off balance sheet commitments to extend credit	42,048	32,321
Overdrafts [Member]
Off balance sheet commitments to extend credit	51,881	33,564
Letters of Credit [Member]
Off balance sheet commitments to extend credit	31,043	24,425
Other Off Balance Sheet Commitments [Member]
Off balance sheet commitments to extend credit	76,028	54,385
Future Loan Commitments [Member]
Off balance sheet commitments to extend credit	$ 311,369	$ 249,318