Note 5 - Loans - Impaired Loans and Related Allowance for Credit Losses (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Loans with no related allowance, unpaid principal balance	$ 95,807	$ 129,970
Loans with no related allowance, recorded investment	88,342	86,374
Loans with related allowance, unpaid principal balance	28,637	50,398
Loans with related allowance, recorded investment	26,732	47,436
Allowance	2,796	7,749
Total impaired loans, unpaid principal balance	124,444	180,368
Total impaired loans, recorded investment	115,074	133,810
Commercial Portfolio Segment [Member]
Loans with no related allowance, unpaid principal balance	24,037	15,493
Loans with no related allowance, recorded investment	23,121	6,721
Loans with related allowance, unpaid principal balance	5,216	7,757
Loans with related allowance, recorded investment	4,640	6,847
Allowance	1,827	530
Real Estate Construction Portfolio Segment [Member]
Loans with no related allowance, unpaid principal balance	5,776	51,290
Loans with no related allowance, recorded investment	5,458	22,002
Commercial Real Estate Portfolio Segment [Member]
Loans with no related allowance, unpaid principal balance	60,522	59,954
Loans with no related allowance, recorded investment	54,453	54,625
Loans with related allowance, unpaid principal balance	10,158	28,258
Loans with related allowance, recorded investment	10,017	27,152
Allowance	573	6,792
Residential Mortgage and Equity Lines Portfolio Segment [Member]
Loans with no related allowance, unpaid principal balance	5,472	3,233
Loans with no related allowance, recorded investment	5,310	3,026
Loans with related allowance, unpaid principal balance	13,263	14,383
Loans with related allowance, recorded investment	12,075	13,437
Allowance	$ 396	$ 427