Note 2 - Investment Securities (Detail) - The Amortized Cost And Estimated Fair Value Of The Securities Portfolio By Contractual Maturity (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Total	$ 820	$ 875
Available For Sale Amortized Cost [Member]
Due in one year or less	918
Due after one year through five years	57,440
Due after five years through ten years	109,844
Due after ten years	28,367
Mortgage-backed securities	360,099
Total	556,668
Available For Sale Estimated Fair Value [Member]
Due in one year or less	921
Due after one year through five years	58,166
Due after five years through ten years	113,430
Due after ten years	28,159
Mortgage-backed securities	370,439
Total	571,115
Held To Maturity Amortized Cost [Member]
Due after ten years	820
Total	820
Held To Maturity Estimated Fair Value [Member]
Due after ten years	956
Total	$ 956