Note 7 - Bank Premises and Equipment, Net (Details Textual) - Branch Buildings [Member] $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Sale Leaseback Transaction, Number of Properties Sold	3	3
Sale Leaseback Transaction, Gain (Loss), Net	$ 48.0	$ 12.7
Sale Leaseback Transaction, Current Period Gain Recognized		6.5
Sale Leaseback Transaction, Deferred Gain, Net		$ 6.2
Sale Leaseback Transaction, Term of Lease		10 years