Note 7 - Loans - Allowance for Loan Losses by Portfolio Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Commercial Portfolio Segment [Member]
Balance	$ 50,590	$ 47,540	$ 56,199	$ 47,501
Provision/(credit) for possible credit losses	4,380	10,040	5,815	11,045
Charge-offs	(3,277)	(3,310)	(12,035)	(6,754)
Recoveries	2,006	607	3,720	3,085
Net (charge-offs)/recoveries	(1,271)	(2,703)	(8,315)	(3,669)
Balance	53,699	54,877	53,699	54,877
Reserve for impaired loans	1,320	7,561	1,320	7,561
Reserve for non-impaired loans	52,379	47,316	52,379	47,316
Reserve for off-balance sheet credit commitments	2,112	703	2,112	703
Real Estate Construction Loans [Member]
Balance	10,753	26,304
Provision/(credit) for possible credit losses	(2,056)	121
Charge-offs
Recoveries	548	41
Net (charge-offs)/recoveries	548	41
Balance	9,245	26,466	9,245	26,466
Commercial Mortgage Loans [Member]
Balance	46,090	67,245
Provision/(credit) for possible credit losses	3,132	(11,762)
Charge-offs	(4,626)	(97)
Recoveries	337	647
Net (charge-offs)/recoveries	(4,289)	550
Balance	44,933	56,033	44,933	56,033
Residential Mortgage and Equity Lines Portfolio Segment [Member]
Balance	15,503	12,323	11,145	11,578
Provision/(credit) for possible credit losses	(5,452)	353	(963)	1,239
Charge-offs			(149)	(161)
Recoveries	6	1	24	21
Net (charge-offs)/recoveries	6	1	(125)	(140)
Balance	10,057	12,677	10,057	12,677
Reserve for impaired loans	375	373	375	373
Reserve for non-impaired loans	9,682	12,304	9,682	12,304
Reserve for off-balance sheet credit commitments	80	37	80	37
Installment and Other Loans [Member ]
Balance	12	25
Provision/(credit) for possible credit losses	(4)	(2)
Charge-offs
Recoveries
Net (charge-offs)/recoveries
Balance	8	23	8	23
Real Estate Construction Portfolio Segment [Member]
Balance			22,170	27,652
Provision/(credit) for possible credit losses			(20,796)	(1,349)
Charge-offs
Recoveries			7,871	163
Net (charge-offs)/recoveries			7,871	163
Balance	9,245	26,466	9,245	26,466
Reserve for impaired loans
Reserve for non-impaired loans	9,245	26,466	9,245	26,466
Reserve for off-balance sheet credit commitments		477		477
Commercial Real Estate Portfolio Segment [Member]
Balance			49,440	74,673
Provision/(credit) for possible credit losses			295	(19,342)
Charge-offs			(5,681)	(3,613)
Recoveries			879	4,315
Net (charge-offs)/recoveries			(4,802)	702
Balance	44,933	56,033	44,933	56,033
Reserve for impaired loans	1,248	6,389	1,248	6,389
Reserve for non-impaired loans	43,685	49,644	43,685	49,644
Reserve for off-balance sheet credit commitments	35	202	35	202
Consumer Portfolio Segment [Member]
Balance			9	16
Provision/(credit) for possible credit losses			(1)	7
Charge-offs
Recoveries
Net (charge-offs)/recoveries
Balance	8	23	8	23
Reserve for impaired loans
Reserve for non-impaired loans	8	23	8	23
Reserve for off-balance sheet credit commitments	2	1	2	1
Balance	122,948	153,437	138,963	161,420
Provision/(credit) for possible credit losses		(1,250)	(15,650)	(8,400)
Charge-offs	(7,903)	(3,407)	(17,865)	(10,528)
Recoveries	2,897	1,296	12,494	7,584
Net (charge-offs)/recoveries	(5,006)	(2,111)	(5,371)	(2,944)
Balance	117,942	150,076	117,942	150,076
Reserve for impaired loans	2,943	14,323	2,943	14,323
Reserve for non-impaired loans	114,999	135,753	114,999	135,753
Reserve for off-balance sheet credit commitments	$ 2,229	$ 1,420	$ 2,229	$ 1,420