Note 5 - Securities (Details) - Securities in a Continuous Loss Position - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Temporarily Impaired Securities:
Securities in a continuous loss position, less than 12 months, fair value	$ 87,334	$ 8,636
Securities in a continuous loss position, less than 12 months, unrealized loss	2,073	67
Securities in a continuous loss position, 12 months or more, fair value	99,981	178,042
Securities in a continuous loss position, 12 months or more, unrealized loss	4,074	5,490
US Government Agencies Debt Securities [Member]
Temporarily Impaired Securities:
Securities in a continuous loss position, less than 12 months, fair value	62,563	6,964
Securities in a continuous loss position, less than 12 months, unrealized loss	1,358	30
Securities in a continuous loss position, 12 months or more, fair value	89,871	156,149
Securities in a continuous loss position, 12 months or more, unrealized loss	3,415	4,709
US States and Political Subdivisions Debt Securities [Member]
Temporarily Impaired Securities:
Securities in a continuous loss position, less than 12 months, fair value	19,803	1,222
Securities in a continuous loss position, less than 12 months, unrealized loss	415	35
Securities in a continuous loss position, 12 months or more, fair value	9,774	19,818
Securities in a continuous loss position, 12 months or more, unrealized loss	605	692
Corporate Debt Securities [Member]
Temporarily Impaired Securities:
Securities in a continuous loss position, less than 12 months, fair value	4,968	450
Securities in a continuous loss position, less than 12 months, unrealized loss	300	2
Securities in a continuous loss position, 12 months or more, fair value	200	1,948
Securities in a continuous loss position, 12 months or more, unrealized loss	1	27
Other Debt Obligations [Member]
Temporarily Impaired Securities:
Securities in a continuous loss position, 12 months or more, fair value	136	127
Securities in a continuous loss position, 12 months or more, unrealized loss	$ 53	$ 62