Note 7 - Loans - Allowance for Loan Losses by Portfolio Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Balance	$ 118,966	$ 138,963
Provision/(credit) for possible credit losses	(2,500)	(10,500)
Charge-offs	(1,759)	(2,329)
Recoveries	837	8,418
Net (charge-offs)/recoveries	(922)	6,089
Balance	115,544	134,552
Reserve for impaired loans	2,275	7,190
Reserve for non-impaired loans	113,269	127,362
Reserve for off-balance sheet credit commitments	3,424	2,694
Commercial Portfolio Segment [Member]
Balance	49,203	56,199
Provision/(credit) for possible credit losses	(1,214)
Charge-offs	(1,204)	(2,070)
Recoveries	491	987
Net (charge-offs)/recoveries	(713)	(1,083)
Balance	47,276	56,381
Reserve for impaired loans	1,062	225
Reserve for non-impaired loans	46,214	56,156
Reserve for off-balance sheet credit commitments	2,243	2,641
Real Estate Construction Portfolio Segment [Member]
Balance	23,268	22,170
Provision/(credit) for possible credit losses	(3,549)	(16,702)
Charge-offs
Recoveries	49	7,276
Net (charge-offs)/recoveries	49	7,276
Balance	19,768	12,744
Reserve for impaired loans
Reserve for non-impaired loans	19,768	12,744
Reserve for off-balance sheet credit commitments	909
Commercial Real Estate Portfolio Segment [Member]
Balance	34,864	49,440
Provision/(credit) for possible credit losses	1,362	978
Charge-offs	(555)	(110)
Recoveries	289	143
Net (charge-offs)/recoveries	(266)	33
Balance	35,960	50,451
Reserve for impaired loans	818	6,593
Reserve for non-impaired loans	35,142	43,858
Reserve for off-balance sheet credit commitments	120	53
Residential Mortgage and Equity Lines Portfolio Segment [Member]
Balance	11,620	11,145
Provision/(credit) for possible credit losses	898	3,961
Charge-offs		(149)
Recoveries	8	12
Net (charge-offs)/recoveries	8	(137)
Balance	12,526	14,969
Reserve for impaired loans	395	372
Reserve for non-impaired loans	12,131	14,597
Reserve for off-balance sheet credit commitments	146
Installment and Other Loans [Member ]
Balance	11	9
Provision/(credit) for possible credit losses	3	(2)
Charge-offs
Recoveries
Net (charge-offs)/recoveries
Balance	14	7
Reserve for impaired loans
Reserve for non-impaired loans	14	7
Reserve for off-balance sheet credit commitments	$ 6
Consumer Portfolio Segment [Member]
Provision/(credit) for possible credit losses		$ 1,265