Note 4 - Investment Securities Available-for-sale (Details) - Securities Available-for-sale by Contractual Maturity (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 375,928	$ 383,665
Estimated Fair Value	378,990	378,133
US Government Agencies Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
One year or less	8,003	19,025
One year or less	8,014	19,133
Amortized Cost	29,290	27,615
Estimated Fair Value	29,811	28,202
Amortized Cost	6,479
Estimated Fair Value	6,563
Residential Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	222,289	234,206
Estimated Fair Value	220,903	228,674
Municipal Bond [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	39,300	25,718
Estimated Fair Value	40,933	26,008
Amortized Cost	66,561	76,705
Estimated Fair Value	68,577	75,732
Ten years through fifteen years	3,610
Ten years through fifteen years	3,802
Equity Investment Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	396	396
Estimated Fair Value	$ 387	$ 384