Note 14 - Tax Expense (Details Textual) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement Line Items [Line Items]
Applicable tax rate	0.00%	0.00%	26.50%
Tax rate effect of expense not deductible in determining taxable profit (tax loss)	15.00%
Net deferred tax assets	$ 65	$ 44
Net deferred tax liabilities	19,620	15,909
South African operations [member]
Statement Line Items [Line Items]
Net deferred tax assets	65	44
Zimbabwean operations [member]
Statement Line Items [Line Items]
Net deferred tax liabilities	$ 19,620	$ 15,909

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- Definition

The applicable income tax rate.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 12
-IssueDate 2017-01-01
-Paragraph 81
-Subparagraph c
-Clause ii
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=12&date=2017-03-01&anchor=para_81_c_ii&doctype=Standard
-URIDate 2017-03-09

+ Details

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- Definition

The amount of deferred tax assets net of deferred tax liabilities, when the absolute amount of deferred tax assets is greater than the absolute amount of deferred tax liabilities. [Refer: Deferred tax assets; Deferred tax liabilities]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 12
-IssueDate 2017-01-01
-Paragraph 81
-Subparagraph g
-Clause i
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=12&date=2017-03-01&anchor=para_81_g_i&doctype=Standard
-URIDate 2017-03-09

+ Details

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- Definition

The amount of deferred tax liabilities net of deferred tax assets, when the absolute amount of deferred tax liabilities is greater than the absolute amount of deferred tax assets. [Refer: Deferred tax assets; Deferred tax liabilities]

+ References

+ Details

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- Definition

The tax rate effect on the reconciliation between the average effective tax rate and the applicable tax rate resulting from the expenses not deductible in determining taxable profit. [Refer: Average effective tax rate; Applicable tax rate]

+ References

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