Note 8 - Loans (Details) - Allowance for Loan Losses by Portfolio Segment - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance	$ 153,437	$ 169,077	$ 161,420	$ 173,889
Provision/(reversal) for possible loan losses	(1,250)	(5,101)	(8,400)	(9,172)
Charge-offs	(3,407)	(1,155)	(10,528)	(12,732)
Recoveries	1,296	6,377	7,584	17,213
Net charge-offs	(2,111)	5,222	(2,944)	4,481
Balance	150,076	169,198	150,076	169,198
Reserve to impaired loans	14,323	13,814	14,323	13,814
Reserve to non-impaired loans	135,753	155,384	135,753	155,384
Reserve for off-balance sheet credit commitments	1,420	2,018	1,420	2,018
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance	47,540	63,239	47,501	65,103
Provision/(reversal) for possible loan losses	10,040	(10,839)	11,045	(12,067)
Charge-offs	(3,310)	(252)	(6,754)	(7,592)
Recoveries	607	4,148	3,085	10,852
Net charge-offs	(2,703)	3,896	(3,669)	3,260
Balance	54,877	56,296	54,877	56,296
Reserve to impaired loans	7,561	2,730	7,561	2,730
Reserve to non-impaired loans	47,316	53,566	47,316	53,566
Reserve for off-balance sheet credit commitments	703	901	703	901
Real Estate Construction Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance	26,304	9,555	27,652	11,999
Provision/(reversal) for possible loan losses	121	25,116	(1,349)	24,460
Charge-offs	0	0	0	(1,813)
Recoveries	41	32	163	57
Net charge-offs	41	32	163	(1,756)
Balance	26,466	34,703	26,466	34,703
Reserve to impaired loans	0	2,604	0	2,604
Reserve to non-impaired loans	26,466	32,099	26,466	32,099
Reserve for off-balance sheet credit commitments	477	668	477	668
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance	67,245	83,395	74,673	84,753
Provision/(reversal) for possible loan losses	(11,762)	(17,950)	(19,342)	(20,991)
Charge-offs	(97)	(903)	(3,613)	(3,327)
Recoveries	647	2,197	4,315	6,304
Net charge-offs	550	1,294	702	2,977
Balance	56,033	66,739	56,033	66,739
Reserve to impaired loans	6,389	7,999	6,389	7,999
Reserve to non-impaired loans	49,604	58,740	49,604	58,740
Reserve for off-balance sheet credit commitments	202	410	202	410
Residential Mortgage and Equity Lines Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance	12,323	12,870	11,578	12,005
Provision/(reversal) for possible loan losses	353	(1,427)	1,239	(562)
Charge-offs	0	0	(161)	0
Recoveries	1	0	21	0
Net charge-offs	1		(140)	0
Balance	12,677	11,443	12,677	11,443
Reserve to impaired loans	373	481	373	481
Reserve to non-impaired loans	12,304	10,962	12,304	10,962
Reserve for off-balance sheet credit commitments	37	39	37	39
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance	25	18	16	29
Provision/(reversal) for possible loan losses	(2)	(1)	7	(12)
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Net charge-offs	0		0	0
Balance	23	17	23	17
Reserve to impaired loans	0	0	0	0
Reserve to non-impaired loans	23	17	23	17
Reserve for off-balance sheet credit commitments	$ 1	$ 0	$ 1	$ 0