Note 6 - Debt and Equity Securities (Details) - Securities Available For Sale by Contractual Maturity (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Securities Available For Sale by Contractual Maturity [Abstract]
Due in one year or less	$ 23,513
Due in one year or less	23,516
Due after one year through five years	35,802
Due after one year through five years	37,050
Due after five years through ten years	68,620
Due after five years through ten years	68,097
Due after ten years	136,864
Due after ten years	139,714
Total other securities	264,799
Total other securities	268,377	261,634
Mortgage-backed securities	702,530
Mortgage-backed securities	704,933	756,156
Total securities available for sale	967,329	1,032,924
Total securities available for sale	$ 973,310	$ 1,017,790