Note 4 - Premises and Equipment, Net (Details) - Summary of Premises and Equipment - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Premises and equipment	$ 72,875,000	$ 71,962,000
Less: accumulated depreciation	25,366,000	23,150,000
Premises and equipment, net	47,509,000	48,812,000
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment	16,598,000	16,579,000
Building [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment	39,349,000	38,761,000
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment	$ 16,928,000	$ 16,622,000