Note 8 - Deposits (Details Textual) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deposit Liabilities, Accrued Interest	$ 2.9	$ 3.4	$ 2.3
Geographic Distribution, Domestic [Member]
Time Deposits, at or Above FDIC Insurance Limit	1,800.0	1,600.0
Geographic Distribution, Foreign [Member]
Time Deposits, at or Above FDIC Insurance Limit	$ 137.7	$ 181.8