Note 6 - Investment Securities (Details) - Investments by Contractual Maturity Date (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Investments by Contractual Maturity Date [Abstract]
Due in one year or less	$ 460,141
Due in one year or less	460,355
Due after one year through five years	98,079
Due after one year through five years	98,283
Due after five years through ten years	119,240
Due after five years through ten years	114,235
Due after ten years (1)	1,102,399	[1]
Due after ten years (1)	1,070,436	[1]
Total	1,779,859		1,290,676
Total	$ 1,743,309		$ 1,291,480

[1] Equity securities are reported in this category