Note 4 - Debt and Equity Securities (Details) - Trust Preferred Issues (USD $) In Thousands, unless otherwise specified					3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2014 Single Issuer [Member]	Mar. 31, 2014 Pooled Issuer 1 [Member]	Mar. 31, 2014 Pooled Issuer 2 [Member]	Mar. 31, 2014 Trust Preferred Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Class					n/a	B1	C1
Performing Banks					1	15	16
Amortized Cost	$ 1,058,903	$ 1,032,924			$ 300	$ 5,617	$ 3,645	$ 9,562
Fair Value	1,053,366	1,017,790			287	3,120	2,900	6,307
Cumulative Credit Related OTTI	$ 3,738	$ 3,738	$ 6,009	$ 6,178		$ 2,196	$ 1,542	$ 3,738
Deferrals/Defaults, Actual as a Percentage of Original Security					0.00%	23.40%	21.30%
Deferrals/Defaults, Expected Percentage of Performing Collateral					0.00%	0.00%	1.50%
Current Lowest Rating					BB-	C	C