Note 6 - Investment Securities (Details) - Investments by Contractual Maturity Date (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Investments by Contractual Maturity Date [Abstract]
Due in one year or less	$ 309,963
Due in one year or less	310,155
Due after one year through five years	185,177
Due after one year through five years	183,982
Due after five years through ten years	152,342
Due after five years through ten years	149,019
Due after ten years (1)	1,396,830	[1]
Due after ten years (1)	1,375,149	[1]
Total	2,044,312		1,290,676
Total	$ 2,018,305		$ 1,291,480

[1] Equity securities are reported in this category