Note 3 - Securities (Detail) - Credit-Related CDO Impairment Losses (USD $) In Thousands, unless otherwise specified	3 Months Ended	63 Months Ended
	Mar. 31, 2012	Mar. 31, 2013
Credit-Related CDO Impairment Losses	$ 721	$ 38,665
No 1 [Member]
Credit-Related CDO Impairment Losses		10,360
No 2 [Member]
Credit-Related CDO Impairment Losses	642	9,402
No 3 [Member]
Credit-Related CDO Impairment Losses	79	2,262
No 4 [Member]
Credit-Related CDO Impairment Losses		1,078
No 5 [Member]
Credit-Related CDO Impairment Losses		8,570
No 6 [Member]
Credit-Related CDO Impairment Losses		243
No 7 [Member]
Credit-Related CDO Impairment Losses		$ 6,750