Note 12 - Commitments and Contingencies (Details Textual) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Commitments To Extend Notional Amount	$ 3,077,081	$ 2,691,579
Commitments to Fund Fixed Rate Loans	182,800
Commitments to Fund Adjustable Rate Loans	$ 2,900,000