Note 9 - Deposits (Details Textual) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Deposit Liabilities, Accrued Interest	$ 13.2	$ 1.7	$ 8.5
Geographic Distribution, Domestic [Member]
Time Deposits, at or Above FDIC Insurance Limit	4,100.0	2,700.0
Geographic Distribution, Foreign [Member]
Time Deposits, at or Above FDIC Insurance Limit	$ 128.6	$ 156.9