Note 3 - Securities (Detail) - Credit-Related CDO Impairment Losses (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Credit-Related CDO Impairment Losses	$ 2,226	$ 936	$ 4,664	$ 24,509	$ 6,330	[1]
Life-to-Date [Member] | No 1 [Member]
Credit-Related CDO Impairment Losses	10,360
Life-to-Date [Member] | No 2 [Member]
Credit-Related CDO Impairment Losses	9,402
Life-to-Date [Member] | No 3 [Member]
Credit-Related CDO Impairment Losses	2,262
Life-to-Date [Member] | No 4 [Member]
Credit-Related CDO Impairment Losses	1,078
Life-to-Date [Member] | No 5 [Member]
Credit-Related CDO Impairment Losses	8,570
Life-to-Date [Member] | No 6 [Member]
Credit-Related CDO Impairment Losses	243
Life-to-Date [Member] | No 7 [Member]
Credit-Related CDO Impairment Losses	6,750
Life-to-Date [Member]
Credit-Related CDO Impairment Losses	38,665
No 1 [Member]
Credit-Related CDO Impairment Losses				8,474	1,886	[1]
No 2 [Member]
Credit-Related CDO Impairment Losses	1,534	525	794	6,549		[1]
No 3 [Member]
Credit-Related CDO Impairment Losses	692	411	142	1,017		[1]
No 4 [Member]
Credit-Related CDO Impairment Losses			684	394		[1]
No 5 [Member]
Credit-Related CDO Impairment Losses			2,801	5,769		[1]
No 6 [Member]
Credit-Related CDO Impairment Losses			243			[1]
No 7 [Member]
Credit-Related CDO Impairment Losses				$ 2,306	$ 4,444	[1]

[1] Amount is shown net of an $18.5 million adjustment recorded on January 1, 2009 pursuant to the adoption of new accounting guidance related to the recognition of OTTI.