Note 7 - Investment Securities (Detail) - The Amortized Cost And Estimated Fair Value Of The Securities Portfolio By Contractual Maturity (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Total	$ 820	$ 820
Available For Sale Amortized Cost [Member]
Due in one year or less	1,028
Due after one year through five years	74,413
Due after five years through ten years	110,584
Due after ten years	26,327
Mortgage-backed securities	342,424
Total	554,776
Available For Sale Estimated Fair Value [Member]
Due in one year or less	1,035
Due after one year through five years	75,501
Due after five years through ten years	113,299
Due after ten years	26,131
Mortgage-backed securities	351,818
Total	567,784
Held To Maturity Amortized Cost [Member]
Due after ten years	820
Total	820
Held To Maturity Estimated Fair Value [Member]
Due after ten years	948
Total	$ 948