Note 5 - Loans (Details) - Allowance for Loan Losses by Portfolio Segment (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]
Provision for possible credit losses	$ (2,122)	$ 10,668	$ 10,385
Charge-offs	(20,442)	(32,791)	(77,626)
Recoveries	14,009	18,127	11,407
Commercial Loans Member
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	66,101	65,658	63,918
Provision for possible credit losses	11,888	16,201	11,711
Charge-offs	(15,625)	(17,707)	(11,745)
Recoveries	2,739	1,949	1,774
Net charge-offs	(12,886)	(15,758)	(9,971)
Ending Balance	65,103	66,101	65,658
Reserve for impaired loans	2,519	1,467	3,336
Reserve for non-impaired loans	62,584	64,634	62,322
Reserve for off-balance sheet credit commitments	909	837	816
Real Estate Construction Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	23,017	21,749	43,262
Provision for possible credit losses	(13,302)	(3,720)	11,514
Charge-offs		(1,165)	(37,500)
Recoveries	2,284	6,153	4,473
Net charge-offs	2,284	4,988	(33,027)
Ending Balance	11,999	23,017	21,749
Reserve for impaired loans	3,460	8,158
Reserve for non-impaired loans	8,539	14,859	21,749
Reserve for off-balance sheet credit commitments	304	390	1,103
Commercial Mortgage Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	82,473	108,021	128,348
Provision for possible credit losses	(2,500)	(23,128)	1,454
Charge-offs	(3,945)	(11,762)	(26,750)
Recoveries	8,725	9,342	4,969
Net charge-offs	4,780	(2,420)	(21,781)
Ending Balance	84,753	82,473	108,021
Reserve for impaired loans	6,584	1,336	2,969
Reserve for non-impaired loans	78,169	81,137	105,052
Reserve for off-balance sheet credit commitments	111	98	113
Residential Mortgage And Equity Lines Member
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	11,703	10,795	9,668
Provision for possible credit losses	924	2,360	2,392
Charge-offs	(872)	(2,132)	(1,456)
Recoveries	250	680	191
Net charge-offs	(622)	(1,452)	(1,265)
Ending Balance	12,005	11,703	10,795
Reserve for impaired loans	721	1,222	1,247
Reserve for non-impaired loans	11,284	10,481	9,548
Reserve for off-balance sheet credit commitments	34	34	34
Installment And Other Loans Member
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	28	57	35
Provision for possible credit losses	(10)	(7)	197
Charge-offs		(25)	(175)
Recoveries	11	3
Net charge-offs	11	(22)	(175)
Ending Balance	29	28	57
Reserve for impaired loans		0
Reserve for non-impaired loans	29	28	57
Reserve for off-balance sheet credit commitments	1	3	3
Total [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	183,322	206,280	245,231
Provision for possible credit losses	(3,000)	(8,294)	27,268
Charge-offs	(20,442)	(32,791)	(77,626)
Recoveries	14,009	18,127	11,407
Net charge-offs	(6,433)	(14,664)	(66,219)
Ending Balance	173,889	183,322	206,280
Reserve for impaired loans	13,284	12,183	7,552
Reserve for non-impaired loans	160,605	171,139	198,728
Reserve for off-balance sheet credit commitments	$ 1,359	$ 1,362	$ 2,069