Note 5 - Loans (Detail) - Allowance for Loan Losses by Portfolio Segment (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Provision for possible credit losses	$ 10,668	$ 10,385	$ 20,139
Charge-offs	(32,791)	(77,626)	(138,755)
Recoveries	18,127	11,407	12,327
Commercial Loans Member
Beginning Balance	65,658	63,918
Provision for possible credit losses	16,201	11,711
Charge-offs	(17,707)	(11,745)
Recoveries	1,949	1,774
Net charge-offs	(15,758)	(9,971)
Ending Balance	66,101	65,658
Reserve for impaired loans	1,467	3,336
Reserve for non-impaired loans	64,634	62,322
Reserve for off-balance sheet credit commitments	837	816
Real Estate Construction Loans [Member]
Beginning Balance	21,749	43,262
Provision for possible credit losses	(3,720)	11,514
Charge-offs	(1,165)	(37,500)
Recoveries	6,153	4,473
Net charge-offs	4,988	(33,027)
Ending Balance	23,017	21,749
Reserve for impaired loans	8,158
Reserve for non-impaired loans	14,859	21,749
Reserve for off-balance sheet credit commitments	390	1,103
Commercial Mortgage Loans [Member]
Beginning Balance	108,021	128,348
Provision for possible credit losses	(23,128)	1,454
Charge-offs	(11,762)	(26,750)
Recoveries	9,342	4,969
Net charge-offs	(2,420)	(21,781)
Ending Balance	82,473	108,021
Reserve for impaired loans	1,336	2,969
Reserve for non-impaired loans	81,137	105,052
Reserve for off-balance sheet credit commitments	98	113
Residential Mortgage And Equity Lines Member
Beginning Balance	10,795	9,668
Provision for possible credit losses	2,360	2,392
Charge-offs	(2,132)	(1,456)
Recoveries	680	191
Net charge-offs	(1,452)	(1,265)
Ending Balance	11,703	10,795
Reserve for impaired loans	1,222	1,247
Reserve for non-impaired loans	10,481	9,548
Reserve for off-balance sheet credit commitments	34	34
Installment And Other Loans Member
Beginning Balance	57	35
Provision for possible credit losses	(7)	197
Charge-offs	(25)	(175)
Recoveries	3
Net charge-offs	(22)	(175)
Ending Balance	28	57
Reserve for impaired loans	0
Reserve for non-impaired loans	28	57
Reserve for off-balance sheet credit commitments	3	3
Total [Member]
Beginning Balance	206,280	245,231
Provision for possible credit losses	(8,294)	27,268
Charge-offs	(32,791)	(77,626)
Recoveries	18,127	11,407
Net charge-offs	(14,664)	(66,219)
Ending Balance	183,322	206,280
Reserve for impaired loans	12,183	7,552
Reserve for non-impaired loans	171,139	198,728
Reserve for off-balance sheet credit commitments	$ 1,362	$ 2,069