Note 5 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 31, 2017
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	34.00%	34.00%
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability		$ (1,200)
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent	0.00%	(14.20%)	0.00%
Income Tax Reconciliation, Foreign Income Tax Witholdings	20.50%	7.10%	0.00%
Liability for Uncertainty in Income Taxes, Current	$ 0			$ 0
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest, Total	7,653	$ 8,177	$ 9,976
Income Tax Examination, Penalties and Interest Accrued, Total	$ 0	0
Open Tax Year	2015 2016 2017 2018
BRAZIL
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest, Total	$ 5,900	$ 8,700
Internal Revenue Service (IRS) [Member] | Domestic Tax Authority [Member]
Tax Credit Carryforward, Amount	$ 0
Income Tax Examination, Year under Examination	2016
California Franchise Tax Board [Member] | State and Local Jurisdiction [Member]
Tax Credit Carryforward, Amount	$ 854
Maximum [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		35.00%
Minimum [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%