Note 7 - Loans - Impaired Loans and Related Allowance for Credit Losses (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Loans with no related allowance, unpaid principal balance	$ 122,264	$ 95,807
Loans with no related allowance, recorded investment	115,182	88,342
Loans with related allowance, unpaid principal balance	33,279	28,637
Loans with related allowance, recorded investment	28,681	26,732
Total impaired loans, unpaid principal balance	155,543	124,444
Total impaired loans, recorded investment	143,863	115,074
Allowance	1,561	2,796
Commercial Portfolio Segment [Member]
Loans with no related allowance, unpaid principal balance	18,200	24,037
Loans with no related allowance, recorded investment	17,826	23,121
Loans with related allowance, unpaid principal balance	3,665	5,216
Loans with related allowance, recorded investment	1,032	4,640
Allowance	145	1,827
Real Estate Construction Portfolio Segment [Member]
Loans with no related allowance, unpaid principal balance	45,545	5,776
Loans with no related allowance, recorded investment	45,057	5,458
Commercial Real Estate Portfolio Segment [Member]
Loans with no related allowance, unpaid principal balance	55,599	60,522
Loans with no related allowance, recorded investment	49,379	54,453
Loans with related allowance, unpaid principal balance	16,515	10,158
Loans with related allowance, recorded investment	15,934	10,017
Allowance	1,018	573
Residential Mortgage and Equity Lines Portfolio Segment [Member]
Loans with no related allowance, unpaid principal balance	2,920	5,472
Loans with no related allowance, recorded investment	2,920	5,310
Loans with related allowance, unpaid principal balance	13,099	13,263
Loans with related allowance, recorded investment	11,715	12,075
Allowance	$ 398	$ 396