Note 5 - Premises and Equipment, Net - Summary of Premises and Equipment (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Property, plant and equipment, gross	$ 74,171,000	$ 72,901,000
Less: accumulated depreciation	28,715,000	26,039,000
Total premises and equipment	45,456,000	46,862,000
Land and Land Improvements [Member]
Property, plant and equipment, gross	17,285,000	16,529,000
Building [Member]
Property, plant and equipment, gross	39,691,000	39,394,000
Furniture and Fixtures [Member]
Property, plant and equipment, gross	$ 17,195,000	$ 16,978,000