Note 5 - Loans Covered By FDIC Loss Share Agreements (Detail) - Accretable Yield for Purchased Loans (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011	Jun. 30, 2012		Jun. 30, 2011
Beginning balance	$ 36,860		$ 31,906	$ 42,833		$ 36,247
Beginning balance	129,755		208,774	158,075	[1]	231,600
Additions	0		0	0		0
Additions	0		0	0		0
Accretable yield adjustments	0		0	0		0
Accretion	(4,994)		(4,347)	(10,967)		(8,688)
Accretion	4,994		4,347	10,967		8,688
Payments and other reductions, net	(20,560)		(20,222)	(54,853)		(47,389)
Balance, ending	31,866		27,559	31,866		27,559
Balance, ending	$ 114,189	[1]	$ 192,899	$ 114,189	[1]	$ 192,899

[1] These loans were not classified as non-performing assets at June 30, 2012 or December 31, 2011, as the loans are accounted for on a pooled basis and the pools are considered to be performing. Therefore, interest income, through accretion of the difference between the carrying amount of the loans and the expected cash flows, is being recognized on all purchased impaired loans. The loans are grouped in pools sharing common risk characteristics and were treated in the aggregate when applying various valuation techniques.