Note 5 - Loans (Details) - Allowance for Loan Losses by Portfolio Segment (USD $) In Thousands, unless otherwise specified	3 Months Ended				12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Provision/(reversal) for possible loan losses	$ (2,000)	$ (5,100)	$ (3,700)	$ (3,000)	$ (10,800)	$ (3,000)	$ (9,000)
Charge-offs					(22,235)	(20,442)	(32,791)
Recoveries					20,938	14,009	18,127
Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance					65,103	66,101
Provision/(reversal) for possible loan losses					(22,244)	11,888
Charge-offs					(7,875)	(15,625)
Recoveries					12,517	2,739
Net charge-offs					4,642	(12,886)
Balance	47,501				47,501	65,103
Reserve to impaired loans	1,263				1,263	2,519
Reserve to non-impaired loans	46,238				46,238	62,584
Reserve for off-balance sheet credit commitments	923				923	909
Real Estate Construction Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance					11,999	23,017
Provision/(reversal) for possible loan losses					19,853	(13,302)
Charge-offs					(6,747)
Recoveries					2,547	2,284
Net charge-offs					(4,200)	2,284
Balance	27,652				27,652	11,999
Reserve to impaired loans	1,077				1,077	3,460
Reserve to non-impaired loans	26,575				26,575	8,539
Reserve for off-balance sheet credit commitments	728				728	304
Commercial Mortgage Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance					84,753	82,473
Provision/(reversal) for possible loan losses					(8,197)	(2,500)
Charge-offs					(7,458)	(3,945)
Recoveries					5,575	8,725
Net charge-offs					(1,883)	4,780
Balance	74,673				74,673	84,753
Reserve to impaired loans	8,993				8,993	6,584
Reserve to non-impaired loans	65,680				65,680	78,169
Reserve for off-balance sheet credit commitments	259				259	111
Residential Mortgage And Equity Lines Member
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance					12,005	11,703
Provision/(reversal) for possible loan losses					(558)	924
Charge-offs					(155)	(872)
Recoveries					286	250
Net charge-offs					131	(622)
Balance	11,578				11,578	12,005
Reserve to impaired loans	465				465	721
Reserve to non-impaired loans	11,113				11,113	11,284
Reserve for off-balance sheet credit commitments	39				39	38
Installment And Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance					29	28
Provision/(reversal) for possible loan losses					(26)	(10)
Recoveries					13	11
Net charge-offs					13	11
Balance	16				16	29
Reserve to impaired loans	0				0
Reserve to non-impaired loans	16				16	29
Reserve for off-balance sheet credit commitments						1
Total [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance					173,889	183,322
Provision/(reversal) for possible loan losses					(11,172)	(3,000)
Charge-offs					(22,235)	(20,442)
Recoveries					20,938	14,009
Net charge-offs					(1,297)	(6,433)
Balance	161,420				161,420	173,889
Reserve to impaired loans	11,798				11,798	13,284
Reserve to non-impaired loans	149,622				149,622	160,605
Reserve for off-balance sheet credit commitments	$ 1,949				$ 1,949	$ 1,363