Statement of cash flows [abstract] Supplementary cash flow information Disclosure of cash flow statement [text block] Disclosure Of General Information About Financial Statements [Abstract] Disclosure Of General Information About Financial Statements [Abstract] Nature of operations Disclosure of general information about financial statements [text block] Disclosure of income tax [Abstract] Disclosure of income tax [Abstract] Reconciliation of accounting profit multiplied by applicable tax rates [abstract] Reconciliation of accounting profit multiplied by applicable tax rates [abstract] Consolidated income before income taxes Profit (loss) before tax Canadian federal and provincial income tax rates Applicable tax rate Income tax expense at statutory rates Tax expense (income) at applicable tax rate Effects of different foreign statutory tax rates and tax holidays Tax effect of foreign tax rates Non-deductible expenditures Tax effect of expense not deductible in determining taxable profit (tax loss) Losses for which no tax benefit has been recorded Tax Effect Of Losses For Which No Tax Benefit Is Recorded Tax Effect Of Losses For Which No Tax Benefit Is Recorded Benefit of optional tax deductions Tax Effect Of Optional Deductions Tax Effect Of Optional Deductions Benefit of optional tax deductions Tax Effect Of Tax Holiday Extension Tax Effect Of Tax Holiday Extension Withholding tax Tax Effect Of Withholding Tax Tax Effect Of Withholding Tax Minimum tax Tax Effect Of Minimum Tax Tax Effect Of Minimum Tax Change due to foreign exchange Tax Effect Of Foreign Exchange Rates Tax Effect Of Foreign Exchange Rates Change in accruals for tax audits Tax Effect Of Changes In Accruals For Tax Audits Tax Effect Of Changes In Accruals For Tax Audits Changes in estimates of deferred tax assets Adjustments for deferred tax of prior periods Non-deductible portion of gains Tax effect of tax losses Amounts under provided for in prior years Adjustments for current tax of prior periods Income tax expense Tax expense (income), continuing operations Current tax expense (income) and adjustments for current tax of prior periods Current tax expense (income) and adjustments for current tax of prior periods Deferred income tax (expense) recovery (Note 16) Deferred tax expense (income) Exploration And Evaluation Of Mineral Resources [Abstract] Exploration And Evaluation Of Mineral Resources [Abstract] Mining interests Disclosure Of Mining Interests [Text Block] Disclosure Of Mining Interests [Text Block] Other Assets1 [Abstract] Other Assets1 [Abstract] Low-grade stockpile Non-current ore stockpiles Debt service reserve account (Note 10) Non-current restricted cash and cash equivalents Loan receivable, including accrued interest Noncurrent Loan And Interest Receivable Noncurrent Loan And Interest Receivable Reclamation deposits Reclamation Deposits Reclamation Deposits Derivative instruments at fair value (Note 14) Non-current derivative financial assets Other Miscellaneous Non-current Other Assets Miscellaneous Non-current Other Assets Other non-current assets Other non-current assets Current financial assets at fair value Current financial assets at fair value through profit or loss Disclosure Of Significant Accounting Policies [Abstract] Disclosure Of Significant Accounting Policies [Abstract] Disclosure of subsidiaries [table] Disclosure of subsidiaries [table] Subsidiaries [axis] Subsidiaries [axis] Subsidiaries [member] Subsidiaries [member] Fekola Fekola Mine [Member] Fekola Mine [Member] Otjikoto Otjikoto Mine [Member] Otjikoto Mine [Member] Masbate Masbate Mine [Member] Masbate Mine [Member] Libertad Libertad Mine [Member] Libertad Mine [Member] Limon Limon Mine [Member] Limon Mine [Member] Kiaka Kiaka Project [Member] Kiaka Project [Member] Disclosure of subsidiaries [line items] Disclosure of subsidiaries [line items] Percentage of ownership interest in subsidiary Proportion of ownership interest in subsidiary Statement of financial position [abstract] Common shares issued (in shares) Number of shares issued Disclosure of temporary difference, unused tax losses and unused tax credits [table] Disclosure of temporary difference, unused tax losses and unused tax credits [table] Geographical areas [axis] Geographical areas [axis] Geographical areas [member] Geographical areas [member] Canada CANADA Colombia COLOMBIA Nicaragua NICARAGUA Maturity [axis] Maturity [axis] Aggregated time bands [member] Aggregated time bands [member] 2019 2019 [Member] 2019 [Member] 2020 2020 [Member] 2020 [Member] 2027 2027 [Member] 2027 [Member] 2028 2028 [Member] 2028 [Member] 2029 2029 [Member] 2029 [Member] 2030 2030 [Member] 2030 [Member] 2031 2031 [Member] 2031 [Member] 2032 2032 [Member] 2032 [Member] 2033 2033 [Member] 2033 [Member] 2034 2034 [Member] 2034 [Member] 2035 2035 [Member] 2035 [Member] 2036 2036 [Member] 2036 [Member] 2037 2037 [Member] 2037 [Member] 2038 2038 [Member] 2038 [Member] No Expiration No Expiration [Member] No Expiration [Member] Disclosure of temporary difference, unused tax losses and unused tax credits [line items] Disclosure of temporary difference, unused tax losses and unused tax credits [line items] Unused tax losses for which no deferred tax asset recognised Unused tax losses for which no deferred tax asset recognised Temporary difference, unused tax losses and unused tax credits [axis] Temporary difference, unused tax losses and unused tax credits [axis] Temporary difference, unused tax losses and unused tax credits [member] Temporary difference, unused tax losses and unused tax credits [member] Capital and non-capital tax losses Capital And Non Capital Tax Loss Related Temporary Differences [Member] Capital And Non Capital Tax Loss Related Temporary Differences [Member] Current assets Current Assets Related Temporary Differences [Member] Current Assets Related Temporary Differences [Member] Debt and share issue costs Debt And Share Issue Costs Related Temporary Differences [Member] Debt And Share Issue Costs Related Temporary Differences [Member] Mine restoration provisions Provisions Related Temporary Differences [Member] Provisions Related Temporary Differences [Member] Mining interests and other Mining Interest And Other Related Temporary Differences [Member] Mining Interest And Other Related Temporary Differences [Member] Long term debt Debt Related Temporary Differences [Member] Debt Related Temporary Differences [Member] Unrecognized deferred tax assets Deductible temporary differences for which no deferred tax asset is recognised Long-Term Debt1 [Abstract] Long-Term Debt1 [Abstract] Disclosure of detailed information about borrowings [table] Disclosure of detailed information about borrowings [table] Retrospective application and retrospective restatement [axis] Retrospective application and retrospective restatement [axis] Currently stated [member] Currently stated [member] Increase (decrease) due to changes in accounting policy required by IFRSs Increase (decrease) due to changes in accounting policy required by IFRSs [member] Classes of financial instruments [axis] Classes of financial instruments [axis] Financial instruments, class [member] Financial instruments, class [member] Convertible senior subordinated notes Convertible Senior Subordinated Notes [Member] Convertible Senior Subordinated Notes [Member] Initially applied IFRSs [axis] Initially applied IFRSs [axis] Initially applied IFRSs [member] Initially applied IFRSs [member] IFRS 9 In accordance with IFRS 9 [member] Carrying amount, accumulated depreciation, amortisation and impairment and gross carrying amount [axis] Carrying amount, accumulated depreciation, amortisation and impairment and gross carrying amount [axis] Carrying amount [member] Carrying amount [member] Principal Gross carrying amount [member] Types of interest rates [axis] Types of interest rates [axis] Interest rate types [member] Interest rate types [member] Fixed interest rate Fixed interest rate [member] Name Of Property [Axis] Name Of Property [Axis] Name Of Property [Axis] Name Of Property [Domain] Name Of Property [Domain] [Domain] for Name Of Property [Axis] Borrowings by name [axis] Borrowings by name [axis] Borrowings by name [member] Borrowings by name [member] Range [axis] Range [axis] Range [Domain] Range [Domain] Range [Domain] Bottom of range Bottom of range [member] Top of range Top of range [member] Disclosure of detailed information about borrowings [line items] Disclosure of detailed information about borrowings [line items] Principal Borrowings Borrowings, interest rate Borrowings, interest rate Conversion ratio Debt Instrument, Convertible, Conversion Ratio Debt Instrument, Convertible, Conversion Ratio Conversion price per share (in usd per share) Debt Instrument, Convertible, Conversion Rate Debt Instrument, Convertible, Conversion Rate Threshold trading days Debt Instrument, Convertible, Threshold Trading Days1 Debt Instrument, Convertible, Threshold Trading Days1 Threshold consecutive trading days Debt Instrument, Convertible, Threshold Consecutive Trading Days11 Debt Instrument, Convertible, Threshold Consecutive Trading Days11 Percentage of conversion price Debt Instrument, Convertible, Percentage Of Conversion Price Debt Instrument, Convertible, Percentage Of Conversion Price Deficit Retained earnings Accumulated other comprehensive loss Accumulated other comprehensive income Measurement period Debt Instrument, Convertible Debt, Measurement Period Debt Instrument, Convertible Debt, Measurement Period Measurement period consecutive trading days Debt Instrument, Convertible Debt, Measurement Period Consecutive Trading Days Debt Instrument, Convertible Debt, Measurement Period Consecutive Trading Days Product of last reported sales price per common share and conversion rate Debt Instrument, Convertible Debt, Product Of Last Reported Sales Price Per Common Share And Conversion Rate Debt Instrument, Convertible Debt, Product Of Last Reported Sales Price Per Common Share And Conversion Rate Unrealized (loss) gain on fair value of convertible notes Gains (losses) recognised in profit or loss on financial liabilities at fair value through profit or loss, designated upon initial recognition or subsequently Interest expense, capitalized to mineral property interests Interest costs capitalised Interest paid Interest paid, classified as financing activities Available-for-sale financial assets [abstract] Disclosure of financial assets [table] Disclosure of financial assets [table] Cost Total Impairment Accumulated impairment [member] Investment Holding [Axis] Investment Holding [Axis] Investment Holding [Domain] Investment Holding [Domain] Calibre Mining Corp. Calibre Mining Corp. [Member] Calibre Mining Corp. [Member] RTG Mining Inc. RTG Mining Inc. [Member] RTG Mining Inc. [Member] St. Augustine Gold & Copper Ltd. St. Augustine Gold & Copper Ltd. [Member] St. Augustine Gold & Copper Ltd. [Member] Libero Copper Corp Libero Copper Corp [Member] Libero Copper Corp [Member] Goldstone Resources Ltd. Goldstone Resources Ltd. [Member] Goldstone Resources Ltd. [Member] Investments in Equity Instruments Designated At Fair Value Through Other Comprehensive Income Investments in equity instruments designated at fair value through other comprehensive income [member] Disclosure of financial assets [line items] Disclosure of financial assets [line items] Investments Non-current investments in equity instruments designated at fair value through other comprehensive income Accumulated other comprehensive loss Disclosure of deferred income [Abstract] Disclosure of deferred income [Abstract] Disclosure of disaggregation of revenue from contracts with customers [table] Disclosure of disaggregation of revenue from contracts with customers [table] Gold Delivery Commitments And Contracts [Axis] Gold Delivery Commitments And Contracts [Axis] Gold Delivery Commitments And Contracts [Axis] Gold Delivery Commitments And Contracts [Domain] Gold Delivery Commitments And Contracts [Domain] [Domain] for Gold Delivery Commitments And Contracts [Axis] 2016 Gold Delivery Contracts 2016 Gold Delivery Contracts [Member] 2016 Gold Delivery Contracts [Member] 2017 Gold Delivery Contract 2017 Gold Delivery Contract [Member] 2017 Gold Delivery Contract [Member] 2016 and 2017 Gold Delivery Contracts 2016 and 2017 Gold Delivery Contracts [Member] 2016 and 2017 Gold Delivery Contracts [Member] Products and services [axis] Products and services [axis] Products and services [member] Products and services [member] Gold and Silver Ores 1040 Gold and Silver Ores [Member] Timing of transfer of goods or services [axis] Timing of transfer of goods or services [axis] Timing of transfer of goods or services [member] Timing of transfer of goods or services [member] 2018 Tranche 1 [Member] Tranche 1 [Member] 2019 Tranche 2 [Member] Tranche 2 [Member] Disclosure of disaggregation of revenue from contracts with customers [line items] Disclosure of disaggregation of revenue from contracts with customers [line items] Proceeds from prepaid sales Adjustments for increase (decrease) in deferred income Prepaid sales contract volume Gold Delivery Commitments And Contracts, Remaining Contractual Volume Gold Delivery Commitments And Contracts, Remaining Contractual Volume Prepaid sales volume delivered Gold Delivery Commitments And Contracts, Contractual Volume Delivered Gold Delivery Commitments And Contracts, Contractual Volume Delivered Deferred revenue earned Gold Delivery Commitments And Contracts, Deferred Revenue Earned Gold Delivery Commitments And Contracts, Deferred Revenue Earned Deferred income Deferred income Disclosure Of Provisions [Abstract] Disclosure Of Provisions [Abstract] Disclosure of fair value measurement of assets [table] Disclosure of fair value measurement of assets [table] Disclosure of fair value measurement of assets [line items] Disclosure of fair value measurement of assets [line items] Discount rate Interest rate, significant unobservable inputs, liabilities Inflation rate Inflation Rate, Significant Unobservable Inputs, Liabilities Inflation Rate, Significant Unobservable Inputs, Liabilities Current estimate to settle mine restoration provisions Current estimate of future cash outflows to be paid to fulfil obligation, significant unobservable inputs, liabilities Disclosure of detailed information about financial instruments [abstract] Details of derivative instruments Disclosure of detailed information about hedging instruments [text block] Disclosure of share capital, reserves and other equity interest [Abstract] Disclosure of share capital, reserves and other equity interest [Abstract] Disclosure of range of exercise prices of outstanding share options [table] Disclosure of range of exercise prices of outstanding share options [table] Ranges of exercise prices for outstanding share options [axis] Ranges of exercise prices for outstanding share options [member] Ranges of exercise prices for outstanding share options [member] 1.12 – 1.99 Exercise Price Range Two [Member] Exercise Price Range Two [Member] 2.00 – 2.99 Exercise Price Range Three [Member] Exercise Price Range Three [Member] 3.00 – 3.99 Exercise Price Range Four [Member] Exercise Price Range Four [Member] 4.00 – 4.99 Exercise Price Range Five [Member] Exercise Price Range Five [Member] Disclosure of range of exercise prices of outstanding share options [line items] Disclosure of range of exercise prices of outstanding share options [line items] Exercise price of outstanding options (in Cdn.$per share) Exercise price of outstanding share options Disclosure of number and weighted average remaining contractual life of outstanding share options [table] Disclosure of number and weighted average remaining contractual life of outstanding share options [table] Ranges of exercise prices for outstanding share options [axis] Disclosure of number and weighted average remaining contractual life of outstanding share options [line items] Disclosure of number and weighted average remaining contractual life of outstanding share options [line items] Number of outstanding options (in shares) Number of share options outstanding in share-based payment arrangement Weighted- average years to expiry (in years) Weighted average remaining contractual life of outstanding share options Weighted-average exercise price (in Cdn.$per share) Weighted average exercise price of share options outstanding in share-based payment arrangement Number of exercisable options (in shares) Number of share options exercisable in share-based payment arrangement Weighted-average exercise price (in Cdn.$per share) Weighted average exercise price of share options exercisable in share-based payment arrangement Analysis of income and expense [abstract] Disclosure Of Expense By Nature [Table] Disclosure Of Expense By Nature [Table] Disclosure Of Expense By Nature [Table] Income Statement Location [Axis] Income Statement Location1 [Axis] Income Statement Location1 [Axis] Income Statement Location [Domain] Income Statement Location1 [Domain] [Domain] for Income Statement Location1 [Axis] General And Administrative Costs General And Administrative Costs [Member] General And Administrative Costs [Member] Disclosure Of Expense By Nature [Line Items] Disclosure Of Expense By Nature [Line Items] [Line Items] for Disclosure Of Expense By Nature [Table] Raw materials and consumables Raw materials and consumables used Contractors Contractor Expense Contractor Expense Salaries and employee benefits Employee benefits expense Electricity Energy transmission charges Equipment rental Rental expense Other Other expenses, by nature Silver credits Revenue from sale of silver Change in inventories Cost of inventories recognised as expense during period Capitalized to mining interests Expense Capitalized To Mining Interest Expense Capitalized To Mining Interest Total Production Expense Production Expense Production Expense Disclosure of detailed information about property, plant and equipment [table] Disclosure of detailed information about property, plant and equipment [table] Measurement Input Type [Axis] Measurement Input Type [Axis] Measurement Input Type [Axis] Measurement Input Type [Domain] Measurement Input Type [Domain] [Domain] for Measurement Input Type [Axis] Long-term gold price Measurement Input, Long-term Gold Price [Member] Measurement Input, Long-term Gold Price [Member] Silver price Measurement Input Type, Silver Price [Member] Measurement Input Type, Silver Price [Member] Copper Price Measurement Input, Copper Price [Member] Measurement Input, Copper Price [Member] Molybdenum Price Measurement Input, Molybdenum Price [Member] Measurement Input, Molybdenum Price [Member] Disclosure of detailed information about property, plant and equipment [line items] Disclosure of detailed information about property, plant and equipment [line items] Fair value inputs price per ounce (in usd per oz) Fair Value Inputs, Price Per Ounce Fair Value Inputs, Price Per Ounce Discount rate Discount rate used in current measurement of fair value less costs of disposal Mine restoration provisions Disclosure of provisions [text block] Long-term investments Disclosure of available-for-sale financial assets [text block] Disclosure of detailed information about financial instruments [table] Disclosure of detailed information about financial instruments [table] Types of financial assets [axis] Types of financial assets [axis] Financial assets, type [member] Financial assets, type [member] Forward contracts Forward contract [member] Types of financial liabilities [axis] Types of financial liabilities [axis] Financial liabilities, type [member] Financial liabilities, type [member] Hedging Designation [axis] Hedging Designation1 [Axis] Hedging Designation1 [Axis] Hedging Designation [Domain] Hedging Designation1 [Domain] [Domain] for Hedging Designation1 [Axis] Not Designated As Hedging Instrument Not Designated As Hedging Instrument [Member] Not Designated As Hedging Instrument [Member] Derivative instrument [Axis] Derivative instrument [Axis] Derivative instrument [Axis] Derivative instrument [Domain] Derivative instrument [Domain] [Domain] for Derivative instrument [Axis] Novated Contracts Under Old RCF Novated Contracts Under Old RCF [Member] Novated Contracts Under Old RCF [Member] Gold Forward Contracts Otjikoto Mine Gold Forward Contracts Otjikoto Mine [Member] Gold Forward Contracts Otjikoto Mine [Member] Disclosure of detailed information about financial instruments [line items] Disclosure of detailed information about financial instruments [line items] Financial liabilities, at fair value Financial liabilities, at fair value Unrealized gain (loss) on derivative instruments Gains (losses) on change in fair value of derivatives Gold forward contracts (in ounces) Derivative, Nonmonetary Notional Amount, Mass1 Derivative, Nonmonetary Notional Amount, Mass1 Average price per ounce (rand) Average Exercise Price Of Derivative Instrument Average Exercise Price Of Derivative Instrument Disclosure of significant subsidiaries Disclosure of subsidiaries [text block] Income and other taxes Disclosure of income tax [text block] Recent accounting pronouncements Disclosure of expected impact of initial application of new standards or interpretations [text block] Inventories [Abstract] Inventories [Abstract] Inventory [Table] Inventory [Table] Inventory [Table] El Limon and La Libertad El Limon And La Libertad [Member] El Limon And La Libertad [Member] Inventory1 [Line Items] Inventory1 [Line Items] [Line Items] for Inventory [Table] Gold and silver bullion Current finished goods In-process inventory Current work in progress Ore stock-pile inventory Current ore stockpiles Materials and supplies Current raw materials and current production supplies Total Inventories Current inventories Net realizable value adjustment Inventory write-down Disclosure of entity's operating segments [Abstract] Disclosure of entity's operating segments [Abstract] Segmented information Disclosure of entity's operating segments [text block] Derivative financial instruments Disclosure of derivative financial instruments [text block] Disclosure of operating segments [table] Disclosure of operating segments [table] Mali MALI Philippines PHILIPPINES Namibia NAMIBIA Burkina Faso BURKINA FASO Finland FINLAND Total Other [Member] Other [Member] Disclosure of operating segments [line items] Disclosure of operating segments [line items] Mining interests Total Property, Plant And Equipment And Joint Ventures Accounted For Using The Equity Method Total Property, Plant And Equipment And Joint Ventures Accounted For Using The Equity Method Statement Of Cash Flows [Table] Statement Of Cash Flows [Table] Statement Of Cash Flows [Table] Components of equity [axis] Components of equity [axis] Equity [member] Equity [member] Deficit Retained earnings [member] Fekola SA Fekola SA [Member] Fekola SA [Member] Kronk Kronk [Member] Kronk [Member] Fekola Equipment Loan Facility Fekola Equipment Loan Facility [Member] Fekola Equipment Loan Facility [Member] Statement Of Cash Flows [Line Items] Statement Of Cash Flows [Line Items] [Line Items] for Statement Of Cash Flows [Table] Non-controlling interest sold in exchange for loan receivable (Note 8) Noncash Transaction, Non-controlling Interest Sold In Exchange For Loan Receivable Noncash Transaction, Non-controlling Interest Sold In Exchange For Loan Receivable Interest on loan to non-controlling interest Interest Income On Loan Receivable To Noncontrolling Interest Interest Income On Loan Receivable To Noncontrolling Interest Share-based payments, capitalized to mineral property interests Share-based Payments Capitalized Share-based Payments Capitalized Change in current liabilities relating to mineral property expenditures Capital Expenditures Incurred But Not Yet Paid1 Capital Expenditures Incurred But Not Yet Paid1 Foreign exchange gains (losses) Foreign exchange gain (loss) Shares issued for purchase of non-controlling interest Issue Of Equity, Purchase Of Non-controlling Interest Issue Of Equity, Purchase Of Non-controlling Interest Restricted cash and cash equivalents Restricted cash and cash equivalents Number of outstanding options, beginning of year (in shares) Number of options granted (in shares) Number of share options granted in share-based payment arrangement Number of options exercised (in shares) Number of share options exercised in share-based payment arrangement Number of options forfeited (in shares) Number of share options forfeited in share-based payment arrangement Number of outstanding options, ending of year (in shares) Weighted-average exercise price, beginning of year (in Cdn.$per share) Weighted average exercise price, options granted (in Cdn.$per share) Weighted average exercise price of share options granted in share-based payment arrangement Weighted average exercise price, options exercised (in Cdn.$per share) Weighted average exercise price of share options exercised in share-based payment arrangement Weighted average exercise price, options forfeited (in Cdn.$per share) Weighted average exercise price of share options forfeited in share-based payment arrangement Weighted-average exercise price, end of year (in Cdn.$per share) Disclosure of fair value measurement [Abstract] Disclosure of fair value measurement [Abstract] Disclosure Of Fair Value Measurement Of Assets And Liabilities [Table] Disclosure Of Fair Value Measurement Of Assets And Liabilities [Table] Disclosure Of Fair Value Measurement Of Assets And Liabilities [Table] Accounts Payable, Derivative Liabilities, Borrowings, and Interest on Borrowings Accounts Payable, Derivative Liabilities, Borrowings, And Interest On Borrowings [Member] Accounts Payable, Derivative Liabilities, Borrowings, And Interest On Borrowings [Member] Revolving credit facility: Revolving Credit Facility1 [Member] Revolving Credit Facility1 [Member] Otjikoto Equipment Loan Facility Otjikoto Equipment Loan Facility [Member] Otjikoto Equipment Loan Facility [Member] Masbate Equipment Loan Facility Masbate Equipment Loan Facility [Member] Masbate Equipment Loan Facility [Member] Finance lease obligations Finance Lease Obligations [Member] Finance Lease Obligations [Member] Nicaraguan equipment loans Nicaraguan Equipment Loans [Member] Nicaraguan Equipment Loans [Member] 2019 Not later than one year [member] 2020 Later than one year and not later than two years [member] 2021 Later than two years and not later than three years [member] 2022 Later than three years and not later than four years [member] 2023 Later than four years and not later than five years [member] Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items] Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items] [Line Items] for Disclosure Of Fair Value Measurement Of Assets And Liabilities [Table] Accounts payable and accrued liabilities Trade and other current payables Derivative liabilities Derivative financial liabilities Interest (estimated) Estimated Interest Payable Estimated Interest Payable Debt repayments Financial liabilities Operating lease commitments Minimum lease payments payable under non-cancellable operating lease Capital expenditure commitments Capital commitments Mine restoration provision Provision for decommissioning, restoration and rehabilitation costs Employee future benefits Provisions for employee benefits Other liabilities Other liabilities Compensation of key management Disclosure of information about key management personnel [text block] Income Tax [Table] Income Tax [Table] Income Tax [Table] Other Income Tax [Line Items] Income Tax [Line Items] [Line Items] for Income Tax [Table] Income tax expense Classes of property, plant and equipment [axis] Classes of property, plant and equipment [axis] Classes Of Property, Plant And Equipment [Domain] Classes Of Property, Plant And Equipment [Domain] Classes Of Property, Plant And Equipment [Domain] Mining property Mining property [member] Gramalote Gramalote [Member] Gramalote [Member] Lynn Lake Royalty Lynn Lake Royalty [Member] Lynn Lake Royalty [Member] Operating activities Cash flows from (used in) operating activities [abstract] Net income for the year Profit (loss) Mine restoration provisions settled (Note 11) Provision used, other provisions Non-cash charges, net (Note 17) Other adjustments for non-cash items Changes in non-cash working capital (Note 17) Increase (decrease) in working capital Proceeds from prepaid sales (Note 13) Changes in long-term value added tax receivables Adjustments For Decrease (Increase) In Receivables From Taxes Other Than Income Tax Noncurrent Adjustments For Decrease (Increase) In Receivables From Taxes Other Than Income Tax, Noncurrent Cash provided by operating activities Cash flows from (used in) operating activities Financing activities Cash flows from (used in) financing activities [abstract] Repayment of convertible notes (Note 10) Repayments Of Convertible Debt1 Repayments Of Convertible Debt1 Revolving credit facility, drawdowns net of transaction costs (Note 10) Proceeds From Lines Of Credit1 Proceeds From Lines Of Credit1 Repayment of revolving credit facility (Note 10) Repayments Of Lines Of Credit1 Repayments Of Lines Of Credit1 Equipment loan facilities, drawdowns net of transaction costs (Note 10) Proceeds From Borrowings Net Of Transaction Costs, Classified as Financing Activities Proceeds From Borrowings Net Of Transaction Costs, Classified as Financing Activities Repayment of equipment loan facilities (Note 10) Repayments of borrowings, classified as financing activities Common shares issued for cash on exercise of stock options (Note 12) Proceeds from exercise of options Interest and commitment fees paid Interest And Commitment Fees Paid, Classified As Financing Activities Interest And Commitment Fees Paid, Classified As Financing Activities Restricted cash movement Cash flows from (used in) decrease (increase) in restricted cash and cash equivalents Other Other inflows (outflows) of cash, classified as financing activities Cash (used) provided by financing activities Cash flows from (used in) financing activities Investing activities Cash flows from (used in) investing activities [abstract] Fekola Mine, including sales proceeds net of pre-production costs Purchase Of Property, Plant And Equipment, Classified As Investing Activities, And Proceeds For Preproduction Sales, Net Purchase Of Property, Plant And Equipment, Classified As Investing Activities, And Proceeds For Preproduction Sales, Net Expenditures on mining interests, development and sustaining capital Purchase of property, plant and equipment, classified as investing activities Expenditures on mining interests, prefeasibility and exploration and development Payments for exploration and evaluation expenses Purchase of non-controlling interest Cash flows used in obtaining control of subsidiaries or other businesses, classified as investing activities Cash proceeds from sale of Lynn Lake royalty, net of transaction costs (Note 8) Proceeds from sales of intangible assets, classified as investing activities Other Other inflows (outflows) of cash, classified as investing activities Cash used by investing activities Cash flows from (used in) investing activities (Decrease) increase in cash and cash equivalents Increase (decrease) in cash and cash equivalents Effect of exchange rate changes on cash and cash equivalents Effect of exchange rate changes on cash and cash equivalents Cash and cash equivalents, beginning of year Cash and cash equivalents Cash and cash equivalents, end of year Fuel derivative contracts Fuel Oil, Gas Oil and Diesel Forward Contracts [Member] Fuel Oil, Gas Oil and Diesel Forward Contracts [Member] Valuation techniques used in fair value measurement [axis] Valuation techniques used in fair value measurement [axis] Valuation techniques [member] Valuation techniques [member] Nicaraguan Cordoba Versus United States Dollar Nicaraguan Cordoba Versus United States Dollar [Member] Nicaraguan Cordoba Versus United States Dollar [Member] Classes of financial liabilities [axis] Classes of financial liabilities [axis] Financial liabilities, class [member] Financial liabilities, class [member] Gold forward contracts (Note 14) Gold Foward Contracts [Member] Gold Foward Contracts [Member] Types of risks [axis] Types of risks [axis] Risks [member] Risks [member] Currency risk Currency risk [member] Commodity price risk Commodity price risk [member] Cash and cash equivalents Cash flows from (used in) operating activities Line of credit facility, maximum borrowing capacity Line Of Credit Facility, Maximum Borrowing Capacity1 Line Of Credit Facility, Maximum Borrowing Capacity1 Borrowings outstanding Undrawn borrowing facilities Undrawn borrowing facilities Change in foreign currency value Increase (Decrease) In Foreign Currency Value Increase (Decrease) In Foreign Currency Value Risk exposure associated with instruments sharing characteristic Risk exposure associated with instruments sharing characteristic Reasonably possible change in risk variable, percent Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Change In Risk Variable, Percent Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Change In Risk Variable, Percent Sensitivity analysis for types of market risk, reasonably possible change in risk variable, impact on cash and cash equivalents Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Change In Risk Variable, Impact On Cash And Cash Equivalents Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Change In Risk Variable, Impact On Cash And Cash Equivalents Sensitivity analysis for types of market risk, reasonably possible change in risk variable, impact on financial liabilities Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Change In Risk Variable, Impact On Financial Liabilities Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Change In Risk Variable, Impact On Financial Liabilities Recent accounting pronouncements Description Of Accounting Policy For Accounting Standards And Amendments Not Yet Adopted [Policy Text Block] Description Of Accounting Policy For Accounting Standards And Amendments Not Yet Adopted [Policy Text Block] Principles of consolidation Disclosure of basis of consolidation [text block] Business combinations Description of accounting policy for business combinations [text block] Goodwill Description of accounting policy for goodwill [text block] Investments in joint arrangements Description of accounting policy for investments in joint ventures [text block] Foreign currency translation Description of accounting policy for foreign currency translation [text block] Financial instruments Description of accounting policy for financial instruments [text block] Impairment of financial assets Description of accounting policy for impairment of financial assets [text block] Inventories Description of accounting policy for measuring inventories [text block] Mining interests Description of accounting policy for property, plant and equipment [text block] Leases Description of accounting policy for leases [text block] Mine restoration provisions Description of accounting policy for decommissioning, restoration and rehabilitation provisions [text block] Share-based payments Description of accounting policy for share-based payment transactions [text block] Current and deferred income taxes Description of accounting policy for income tax [text block] Revenue Description of accounting policy for recognition of revenue [text block] Earnings per share Description of accounting policy for earnings per share [text block] Ore reserve and resource estimates Description Of Accounting Policy For Ore Reserve And Resource Estimates [Policy Text Block] Description Of Accounting Policy For Ore Reserve And Resource Estimates [Policy Text Block] Value-added tax receivables Description of accounting policy for taxes other than income tax [text block] Deferred income taxes and valuation allowances Description of accounting policy for deferred income tax [text block] Impairment of long-lived assets Description of accounting policy for impairment of assets [text block] Exploration and evaluation expenditures Description of accounting policy for exploration and evaluation expenditures [text block] Accounts receivable and prepaids Adjustments For Decrease (Increase) In Receivables And Other Current Assets Adjustments For Decrease (Increase) In Receivables And Other Current Assets Value-added and other tax receivables Adjustments For Decrease (Increase) In Receivables From Taxes Other Thank Income Tax Current Adjustments For Decrease (Increase) In Receivables From Taxes Other Than Income Tax, Current Inventories Adjustments for decrease (increase) in inventories Accounts payable and accrued liabilities Adjustments for increase (decrease) in trade and other payables Current income and other taxes payable Adjustments For Increase (Decrease) In Current Tax Liabilities Current Adjustments For Increase (Decrease) In Current Tax Liabilities, Current Changes in non-cash working capital Toega, Burkina Faso Toega, Burkina Faso [Member] Toega, Burkina Faso [Member] Fekola Regional Fekola Regional [Member] Fekola Regional [Member] Ondundu Ondundu, Nambibia [Member] Ondundu, Nambibia [Member] Finland Properties, Finland Finland Properties, Finland [Member] Finland Properties, Finland [Member] Other Other Projects [Member] Other Projects [Member] Other exploration and development Disclosure of operating segments Disclosure of operating segments [text block] Other assets Disclosure of other assets [text block] Deferred tax asset Deferred tax assets Deferred tax liability Deferred tax liabilities Total deferred tax liability (asset) Deferred tax liability (asset) Schedule of current inventories Schedule Of Inventory, Current1 [Table Text Block] Schedule Of Inventory, Current1 [Table Text Block] Assets Assets [abstract] Current Current assets [abstract] Accounts receivable, prepaids and other Receivables And Other Current Assets Receivables And Other Current Assets Value-added and other tax receivables Current receivables from taxes other than income tax Inventories (Note 6) Current assets Current assets Long-term investments (Note 7) Non-current financial assets available-for-sale Value-added tax receivables Non-current value added tax receivables Mining interests - owned by subsidiaries Property, plant and equipment Investments in joint ventures (accounted for using the equity method) Investments in joint ventures accounted for using equity method Other assets (Note 9) Deferred income taxes (Note 16) Total assets Assets Liabilities Liabilities [abstract] Current Current liabilities [abstract] Current income and other taxes payable Current tax liabilities, current Current portion of derivative instruments at fair value (Note 14) Current derivative financial liabilities Current portion of long-term debt (Note 10) Current borrowings and current portion of non-current borrowings Current portion of prepaid sales (Note 13) Deferred income classified as current Current portion of mine restoration provisions (Note 11) Current provision for decommissioning, restoration and rehabilitation costs Other current liabilities Other current liabilities Total current liabilities Current liabilities Derivative instruments at fair value (Note 14) Non-current derivative financial liabilities Long-term debt (Note 10) Non-current portion of non-current borrowings Prepaid sales (Note 13) Deferred income classified as non-current Mine restoration provisions (Note 11) Non-current provision for decommissioning, restoration and rehabilitation costs Deferred income taxes (Note 16) Employee benefits obligation Non-current provisions for employee benefits Other long-term liabilities Other non-current liabilities Total liabilities Liabilities Equity Equity [abstract] Shareholders’ equity Shareholders' Equity [Abstract] Shareholders' Equity [Abstract] Share capital issued: 994,621,917 common shares (Dec 31, 2017 – 980,932,908) Issued capital Contributed surplus Additional paid-in capital Equity attributable to owners of parent Equity attributable to owners of parent Non-controlling interests Non-controlling interests Total equity Equity Total equity and liabilities Equity and liabilities Commitments (Note 21) Commitments And Contingencies1 Commitments And Contingencies1 Disclosure of other provisions Disclosure of other provisions [text block] Profit or loss [abstract] Gold revenue Revenue from sale of gold Cost of sales Cost of Sales [Abstract] Cost of Sales [Abstract] Production costs (Note 19) Depreciation and depletion Cost of Sales, Depreciation and Amortisation Expense Cost of Sales, Depreciation and Amortisation Expense Royalties and production taxes Royalty Expense And Production Tax Expense Royalty Expense And Production Tax Expense Total cost of sales Cost of sales Gross profit Gross profit General and administrative Selling, general and administrative expense Share-based payments (Note 12) Expense from share-based payment transactions in which goods or services received did not qualify for recognition as assets Impairment of long-lived assets, net (Note 8) Impairment loss recognised in profit or loss, property, plant and equipment Gain on sale of Lynn Lake royalty (Note 8) Gains (Losses) On Disposals Of Net Smelter Royalty Gains (Losses) On Disposals Of Net Smelter Royalty Write-down of mineral property interests (Note 8) Impairment Loss Recognised In Profit Or Loss, Mineral Properties Impairment Loss Recognised In Profit Or Loss, Mineral Properties Provision for non-recoverable input taxes Tax expense other than income tax expense Other Miscellaneous other operating expense Operating income Profit (loss) from operating activities Unrealized gain (loss) on fair value of convertible notes (Note 10) Gains (Losses) Recognised In Profit Or Loss On Convertible Notes At Fair Value Through Profit Or Loss Designated Upon Initial Recognition Or Subsequently Gains (Losses) Recognised In Profit Or Loss On Convertible Notes At Fair Value Through Profit Or Loss Designated Upon Initial Recognition Or Subsequently Community relations Community Relations Expense Community Relations Expense Interest and financing expense Finance costs Realized gain (loss) on derivative instruments Gains (Losses) Recognised In Profit Or Loss On Financial Liabilities At Fair Value Through Profit Or Loss, Designated Upon Initial Recognition Or Subsequently, Derivative Financial Liability Gains (Losses) Recognised In Profit Or Loss On Financial Liabilities At Fair Value Through Profit Or Loss, Designated Upon Initial Recognition Or Subsequently, Derivative Financial Liability Unrealized (loss) gain on derivative instruments (Note 14) Write-down of long-term investments Impairment loss on financial assets Other Miscellaneous Other Non-operating Expense Miscellaneous Other Non-operating Expense Income before taxes Current income tax, withholding and other taxes (Note 16) Current tax expense (income) Net income for the year Attributable to: Profit (loss), attributable to [abstract] Net income (loss), attributable to Shareholders of the Company Profit (loss), attributable to owners of parent Net income (loss), attributable to Non-controlling interests Profit (loss), attributable to non-controlling interests Earnings per share (attributable to shareholders of the Company) Earnings per share [abstract] Basic (in USD per share) Basic earnings (loss) per share Diluted (in USD per share) Diluted earnings (loss) per share Weighted average number of common shares outstanding (in thousands) Weighted average ordinary shares and adjusted weighted average ordinary shares [abstract] Basic (in shares) Weighted average number of ordinary shares outstanding Diluted (in shares) Adjusted weighted average number of ordinary shares outstanding Schedule of Other Assets Schedule Of Other Assets1 [Table Text Block] Schedule Of Other Assets1 [Table Text Block] Schedule of Long-Term Investments Schedule Of Long-Term Investments [Table Text Block] Schedule Of Long-Term Investments [Table Text Block] Entities [Table] Entities [Table] Entity Information [Line Items] Entity Information [Line Items] Number of operating mines Number Of Operating Mines Number Of Operating Mines Proportion of ownership interest in joint venture Proportion of ownership interest in joint venture Disclosure of detailed information about property, plant and equipment [abstract] Central Bank Of West African States Prime Rate Central Bank Of West African States Prime Rate [Member] Central Bank Of West African States Prime Rate [Member] Receivables From Sale Of Properties Receivables From Sale Of Properties [Member] Receivables From Sale Of Properties [Member] Classes of share capital [axis] Classes of share capital [axis] Share capital Share capital [member] Non-participating Share Capital Non-participating Share Capital [Member] Non-participating Share Capital [Member] Fully Participating Share Capital Fully Participating Share Capital [Member] Fully Participating Share Capital [Member] Interest rate risk Interest rate risk [member] Counterparties [axis] Counterparties [axis] Counterparties [member] Counterparties [member] Triton Minera S.A. Triton Minera S.A. [Member] Triton Minera S.A. [Member] Continuing and discontinued operations [axis] Continuing and discontinued operations [axis] Aggregate continuing and discontinued operations [member] Aggregate continuing and discontinued operations [member] Discontinued operations Discontinued operations [member] Business combinations [axis] Business combinations [axis] Business combinations [member] Business combinations [member] Central Sun Central Sun [Member] Central Sun [Member] Mocoa Mocoa [Member] Mocoa [Member] Pampa Paciencia And Cerro Barco Pampa Paciencia And Cerro Barco [Member] Pampa Paciencia And Cerro Barco [Member] Namibia and Mali Namibia And Mali [Member] Namibia And Mali [Member] Property, plant and equipment Property, plant and equipment [member] Exploration and evaluation properties (non-depletable) Exploration and evaluation assets [member] Property, plant and equipment (depletable) Mining Property, Depletable [Member] Mining Property, Depletable [Member] Proportion of ownership interest in associate Proportion of ownership interest in associate Impairment loss Tax effect of impairment in property, plant and equipment Tax Effect Of Reversal Of Impairment In Property, Plant And Equipment Tax Effect Of Reversal Of Impairment In Property, Plant And Equipment Impairment loss, net of tax Impairment Loss Recognised In Profit Or Loss, Property, Plant And Equipment, Net Of Tax Impairment Loss Recognised In Profit Or Loss, Property, Plant And Equipment, Net Of Tax Reversal of impairment loss Reversal of impairment loss recognised in profit or loss, property, plant and equipment Reversal of impairment loss, net of tax Reversal Of Impairment Loss Recognised In Profit Or Loss, Property, Plant And Equipment, Net Of Tax Reversal Of Impairment Loss Recognised In Profit Or Loss, Property, Plant And Equipment, Net Of Tax Property, plant and equipment Number of shares received (in shares) Portion Of Consideration Paid (Received) Consisting Of Equity Shares, Shares Portion Of Consideration Paid (Received) Consisting Of Equity Shares, Shares Proceeds from sale of property, plant and equipment Portion Of Consideration Paid (Received) Consisting Of Equity Shares, Value Portion Of Consideration Paid (Received) Consisting Of Equity Shares, Value Net smelter royalty receivable Portion Of Consideration Paid (Received) Consisting Of Royalty Agreement, Percentage Portion Of Consideration Paid (Received) Consisting Of Royalty Agreement, Percentage Net smelter royalty recognized as of acquisition date Net Smelter Royalty Recognized As Of Acquisition Date Net Smelter Royalty Recognized As Of Acquisition Date Proportion of ownership interests held by non-controlling interests Proportion of ownership interests held by non-controlling interests Reasonably possible change in price per unit (in usd per unit) Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Change In Risk Variable, Price Per Unit Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Change In Risk Variable, Price Per Unit Reasonably possible change in risk variable impact on property, plant and equipment Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Change In Risk Variable, Impact On Property, Plant And Equipment Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Change In Risk Variable, Impact On Property, Plant And Equipment Sales proceeds from pre-commercial production period Revenue Offset Against Capitalized Costs Revenue Offset Against Capitalized Costs Priority dividend rate to non-controlling interest Priority Dividend Rate, Non-Controlling Interest Priority Dividend Rate, Non-Controlling Interest Consideration paid (received) Consideration paid (received) Gain (loss) on sale of mineral properties Gains (losses) on disposals of property, plant and equipment Receivables from sale of properties Receivables from sale of properties Borrowings, adjustment to interest rate basis Borrowings, adjustment to interest rate basis Acquisition of non-controlling interest (Note 8) Reclass Increase (decrease) through transfers and other changes, property, plant and equipment Net smelter royalty Business Combinations, Net Smelter Royalty Business Combinations, Net Smelter Royalty Increase (decrease) in contingent consideration asset (liability) Increase (decrease) in contingent consideration asset (liability) Contingent consideration period Disposal Group, Contingent Consideration Period Disposal Group, Contingent Consideration Period Gain on sale of Lynn Lake royalty (Note 8) Write-down mineral property interests Disclosure of Major Components of Tax Expense (Income) Disclosure Of Major Components Of Tax Expense (Income) [Table Text Block] Disclosure Of Major Components Of Tax Expense (Income) [Table Text Block] Disclosure of Income Tax by Geographical Jurisdiction Disclosure Of Income Tax By Geographical Jurisdiction [Table Text Block] Disclosure Of Income Tax By Geographical Jurisdiction [Table Text Block] Disclosure of temporary difference, unused tax losses and unused tax credits Disclosure of temporary difference, unused tax losses and unused tax credits [text block] Disclosure of Unrecognized Temporary Difference, Unused Tax Losses and Unused Tax Credits Disclosure Of Unrecognized Temporary Difference, Unused Tax Losses And Unused Tax Credits [Table Text Block] Disclosure Of Unrecognized Temporary Difference, Unused Tax Losses And Unused Tax Credits [Table Text Block] Profit (loss), attributable to owners of parent Dilutive impact of gain on fair value of convertible notes Adjustment To Profit (Loss) For Gain On Fair Value Of Convertible Notes Adjustment To Profit (Loss) For Gain On Fair Value Of Convertible Notes Diluted net income for the year (attributable to shareholders of the Company) Profit (loss), attributable to ordinary equity holders of parent entity including dilutive effects Basic weighted average number of shares outstanding (in shares) Effect of dilutive convertible notes (in shares) Dilutive effect of convertible instruments on number of ordinary shares Effect of dilutive securities, stock options (in shares) Dilutive effect of share options on number of ordinary shares Effect of dilutive securities, restricted share units (in shares) Dilutive Effect Of Restricted Stock Units On Number Of Ordinary Shares Dilutive Effect Of Restricted Stock Units On Number Of Ordinary Shares Diluted weighted average number of shares outstanding (in shares) Earnings (loss) per share (attributable to Shareholders of the Company), Basic (in USD per share) Earnings (loss) per share (attributable to Shareholders of the Company), Diluted (in USD per share) Prepaid Sales Disclosure of deferred income [text block] Production costs by nature Disclosure of cost of sales [text block] Fair value adjustment Fair Value Adjustment [Member] Fair Value Adjustment [Member] Unamortized Transaction Costs Unamortized Transaction Costs [Member] Unamortized Transaction Costs [Member] Convertible senior subordinated notes: Otjikoto equipment loan facility (net of unamortized transaction costs) Equipment loans/finance lease obligations: Equipment Loans And Finance Lease Obligations [Member] Equipment Loans And Finance Lease Obligations[Member] Principal Current portion of long-term debt Long-term debt Summary of significant accounting policies Disclosure of significant accounting policies [text block] Statement of changes in equity [abstract] Statement of changes in equity [table] Statement of changes in equity [table] Share capital Issued capital [member] Contributed surplus Additional paid-in capital [member] Accumulated other comprehensive loss Accumulated other comprehensive income [member] Non- controlling interests Non-controlling interests [member] Statement of changes in equity [line items] Statement of changes in equity [line items] Beginning balance number of shares outstanding (in shares) Number of shares outstanding Beginning balance equity IFRS 9 transition adjustment on January 1, 2018 (Note 3) Increase (Decrease) Through Adoption Of New Accounting Principle Increase (Decrease) Through Adoption Of New Accounting Principle Impact of change in credit spread on convertible notes (Note 10) Other comprehensive income, net of tax, change in fair value of financial liability attributable to change in credit risk of liability Unrealized gain (loss) on investments, net of deferred tax expense Other comprehensive income, net of tax, gains (losses) from investments in equity instruments Number of shares issued on exercise of stock options (in shares) Shares issued on exercise of stock options (Note 12) Increase (decrease) through exercise of options, equity Shares pending issuance on exercise of stock options (in shares) Number Of Shares Pending Due to Options Exercised In Share-Based Payment Arrangement Number Of Shares Pending Due to Options Exercised In Share-Based Payment Arrangement Shares pending issuance on exercise of stock options Pending Increase (Decrease) In Shares Through Exercise Of Options, Equity Pending Increase (Decrease) In Shares Through Exercise Of Options, Equity Shares issued on vesting of RSUs (in shares) Number of other equity instruments exercised or vested in share-based payment arrangement Shares issued on vesting of RSUs (Note 12) Increase (Decrease) Through Vesting Of Restricted Stock Units, Equity Increase (Decrease) Through Vesting Of Restricted Stock Units, Equity Payments received from non-controlling interest Proceeds from contributions of non-controlling interests Acquisition of non-controlling interest (Note 8) Increase (Decrease) Through Purchase of Non-controlling Interest Increase (Decrease) Through Purchase of Non-controlling Interest Sale of non-controlling interest (Note 8) Increase (decrease) through changes in ownership interests in subsidiaries that do not result in loss of control, equity Net loan receivable on sale of non-controlling interest (Note 8) Issuance Of Loan Receivable To Noncontrolling Interest Issuance Of Loan Receivable To Noncontrolling Interest Shares issued for mineral property interests (in shares) Number Of Shares Issued For Mineral Interests Number Of Shares Issued For Mineral Interests Shares issued for mineral property interest Stock Issued Stock Issued Shares issued for non-controlling interest (in shares) Number Of Shares Issued For Purchase Of Noncontrolling Interest Number Of Shares Issued For Purchase Of Noncontrolling Interest Shares issued for purchase of non-controlling interest Share-based payments (Note 12) Increase (decrease) through share-based payment transactions, equity Transfer to share capital on exercise of stock options Increase (Decrease) Through Transfer Between Share Capital And Contributed Surplus, Equity Increase (Decrease) Through Transfer Between Share Capital And Contributed Surplus, Equity Ending balance number of shares outstanding (in shares) Ending balance equity 2019 Next Twelve Months [Member] Next Twelve Months [Member] 2020 Year Two [Member] Year Two [Member] Total 2017-2019 [Member] 2017-2019 [Member] Forward – fuel oil: Fuel Oil Forward Contract [Member] Fuel Oil Forward Contract [Member] Forward – gas oil: Gas Oil Forward Contract [Member] Gas Oil Forward Contract [Member] Forward – diesel: Diesel Forward Contract [Member] Diesel Forward Contract [Member] Forward fuel contracts Derivative, Nonmonetary Notional Amount, Volume1 Derivative, Nonmonetary Notional Amount, Volume1 Average price per litre (in usd per litre) Disclosure of components of cost of sales Disclosure Of Components Of Cost Of Sales [Table Text Block] Disclosure Of Components Of Cost Of Sales [Table Text Block] Disclosure of detailed information about property, plant and equipment Disclosure of detailed information about property, plant and equipment [text block] Disclosure of significant unobservable inputs used in fair value measurement of assets Disclosure of significant unobservable inputs used in fair value measurement of assets [text block] Mobile Equipment, Tailings Dam and Equipment Mobile Equipment, Tailings Dam And Equipment [Member] Mobile Equipment, Tailings Dam And Equipment [Member] Useful lives of property, plant and equipment Useful Lives Or Depreciation Rates, Property, Plant And Equipment, Period Useful Lives Or Depreciation Rates, Property, Plant And Equipment, Period Accounting Judgements And Estimates [Abstract] Accounting Judgements And Estimates [Abstract] Significant accounting judgements and estimates Disclosure of accounting judgements and estimates [text block] Salaries and short-term employee benefits Key management personnel compensation, short-term employee benefits Share-based payments Key management personnel compensation, share-based payment Key management personnel compensation Key management personnel compensation Mocoa Royalty, Colombia Mocoa Royalty Interest [Member] Mocoa Royalty Interest [Member] Finland Other Other property, plant and equipment [member] Undeveloped mineral interests Mining Assets, Non-depletable [Member] Mining Assets, Non-depletable [Member] Mine under construction (non-depletable) Mining Assets, Construction In Progress [Member] Mining Assets, Construction In Progress [Member] Office, furniture and equipment, net Office equipment [member] Accumulated depreciation and depletion Accumulated depreciation and amortisation [member] Reconciliation of changes in property, plant and equipment [abstract] Reconciliation of changes in property, plant and equipment [abstract] Property, plant and equipment, beginning balance Additions Additions other than through business combinations, property, plant and equipment Depreciation Depreciation, property, plant and equipment Disposals / write-offs / impairments Disposals, property, plant and equipment Property, plant and equipment, ending balance Reconciliation Of Changes In Joint Ventures Accounted For Using Equity Method [Roll Forward] Reconciliation Of Changes In Joint Ventures Accounted For Using Equity Method [Roll Forward] Reconciliation Of Changes In Joint Ventures Accounted For Using Equity Method [Roll Forward] Investments in joint ventures (accounted for using the equity method) beginning balance Additions Additions other than through business combinations, investment property Disposals / write-offs / impairments Disposals, investment property Investments in joint ventures (accounted for using the equity method) ending balance Reconciliation Of Changes In Property, Plant And Equipment And Joint Ventures Accounted For Using Equity Method [Roll Forward] Reconciliation Of Changes In Property, Plant And Equipment And Joint Ventures Accounted For Using Equity Method [Roll Forward] Reconciliation Of Changes In Property, Plant And Equipment And Joint Ventures Accounted For Using Equity Method [Roll Forward] Total property, plant and equipment and joint ventures, beginning balance Additions Additions Other Than Through Business Combinations, Property, Plant And Equipment And Investments In Joint Ventures Accounted For Using Equity Method Additions Other Than Through Business Combinations, Property, Plant And Equipment And Investments In Joint Ventures Accounted For Using Equity Method Disposals / write-offs / impairments Disposals, Property, Plant And Equipment And Investments In Joint Ventures Accounted For Using Equity Method Disposals, Property, Plant And Equipment And Investments In Joint Ventures Accounted For Using Equity Method Total property, plant and equipment and joint ventures, ending balance Share capital Disclosure of share capital, reserves and other equity interest [text block] Disclosure of changes in accounting policies Disclosure of changes in accounting policies [text block] Financial instruments Disclosure of financial instruments [text block] Non-adjusting events after reporting period [axis] Non-adjusting events after reporting period [axis] Non-adjusting events after reporting period [member] Non-adjusting events after reporting period [member] Entering into significant commitments or contingent liabilities Entering into significant commitments or contingent liabilities [member] Financial assets, at fair value Financial assets, at fair value Depreciation and depletion Adjustments for depreciation and amortisation expense Delivery into prepaid sales (Note 13) Share-based payments (Note 12) Adjustments for share-based payments Impairment of long-lived assets, net (Note 8) Gain on sale of Lynn Lake royalty (Note 8) Write-down of mineral property interests (Note 8) Adjustments for impairment loss (reversal of impairment loss) recognised in profit or loss, exploration and evaluation assets Provision for non-recoverable input taxes Unrealized (gain) loss on fair value of convertible notes (Note 10) Interest and financing expense Interest expense Unrealized loss (gain) on derivative instruments (Note 14) Adjustments for gains (losses) on change in fair value of derivatives Write-down of long-term investments Deferred income tax expense (recovery) (Note 16) Adjustments for deferred tax expense Other Other adjustments to reconcile profit (loss) Non-cash (credits) charges Inventories Disclosure of inventories [text block] Swap contract Swap contract [member] Interest rate swaps Interest rate swap contract [member] Notional amount of interest rate swaps Derivative, Notional Amount Derivative fixed interest rate Derivative, Fixed Interest Rate1 Derivative, Fixed Interest Rate1 Segment consolidation items [axis] Segment consolidation items [axis] Entity's total for segment consolidation items [member] Entity's total for segment consolidation items [member] Operating segments Operating segments [member] Segments [axis] Segments [axis] Segments [member] Segments [member] Other Mineral Properties Other Mineral Properties [Member] Other Mineral Properties [Member] Corporate & Other Corporate and Other [Member] Corporate and Other [Member] Intersegment gold revenue Intersegment Revenue Intersegment Revenue Production costs Depreciation & depletion Depreciation and amortisation expense Impairment (reversal) of long-lived assets Write-downs (reversals of write-downs) of property, plant and equipment Current income tax, withholding and other taxes Capital expenditures Payments For Capital Expenditures Payments For Capital Expenditures Total assets Interest Principal and interest payable Borrowings And Interest Payable Borrowings And Interest Payable Disclosure of employee benefits Disclosure Of Detailed Information About Key Management Personnel [Table Text Block] Disclosure Of Detailed Information About Key Management Personnel [Table Text Block] Disclosure Of Commitments [Abstract] Disclosure Of Commitments [Abstract] Capital Spares Capital Spares [Member] Capital Spares [Member] Mobile Equipment Mobile Equipment [Member] Mobile Equipment [Member] Oxygen Plant Oxygen Plant [Member] Oxygen Plant [Member] Plant Expansion Plant Expansion [Member] Plant Expansion [Member] Tailings Storage Facility Tailings Storage Facility [Member] Tailings Storage Facility [Member] Disclosure of debt instruments Disclosure of debt instruments [text block] Disclosure Of Long-Term Debt Maturities Disclosure Of Long-Term Debt Maturities [Table Text Block] Disclosure Of Long-Term Debt Maturities [Table Text Block] Mining Interest Schedule Disclosure of property, plant and equipment [text block] Commitments Disclosure of commitments [text block] Disclosure Of Basis Of Preparation Of Financial Statements [Abstract] Disclosure Of Basis Of Preparation Of Financial Statements [Abstract] Basis of preparation Disclosure of basis of preparation of financial statements [text block] Statement of comprehensive income [abstract] Other comprehensive income Other comprehensive income [abstract] Unrealized (loss) gain on investments, net of deferred tax expense (Note 7) Other comprehensive (loss) income for the year Other comprehensive income Total comprehensive income for the year Comprehensive income Other comprehensive (loss) income attributable to: Other Comprehensive Income Attributable To [Abstract] Other Comprehensive Income Attributable To [Abstract] Shareholders of the Company Other comprehensive income, attributable to owners of parent Non-controlling interests Other comprehensive income, attributable to non-controlling interests Total comprehensive income attributable to: Comprehensive income attributable to [abstract] Shareholders of the Company Comprehensive income, attributable to owners of parent Non-controlling interests Comprehensive income, attributable to non-controlling interests Capital Losses Capital Losses [Member] Capital Losses [Member] Income tax relating to priority dividend Income Tax Relating To Priority Dividend Income Tax Relating To Priority Dividend Income taxes paid Income taxes paid (refund) Disclosure of other provisions [table] Disclosure of other provisions [table] Classes of other provisions [axis] Classes of other provisions [axis] Other provisions [member] Other provisions [member] Mine restoration provisions Provision for decommissioning, restoration and rehabilitation costs [member] Disclosure of other provisions [line items] Disclosure of other provisions [line items] Reconciliation of changes in other provisions [abstract] Reconciliation of changes in other provisions [abstract] Balance, beginning of year Other provisions Reclamation spending Accretion expense Increase through adjustments arising from passage of time, other provisions Change in obligation Increase in existing provisions, other provisions Balance, end of year Current portion of mine restoration provisions Non-current portion of mine restoration provisions Long-term debt Disclosure of borrowing costs [text block] Disclosure Of Supplementary Cash Flow Information Disclosure Of Supplementary Cash Flow Information [Table Text Block] Disclosure Of Supplementary Cash Flow Information [Table Text Block] Beginning balance deferred tax liability (asset) Deferred tax expense (income) Amount charged to OCI Income tax relating to components of other comprehensive income Net change in deferred taxes Net Change In Deferred Taxes Net Change In Deferred Taxes Ending balance deferred tax liability (asset) Document and Entity Information [Abstract] Document and Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding (in shares) Entity Common Stock, Shares Outstanding Entity Current Reporting Status Entity Current Reporting Status Disclosure of terms and conditions of share-based payment arrangement [table] Disclosure of terms and conditions of share-based payment arrangement [table] Types of share-based payment arrangements [axis] Types of share-based payment arrangements [axis] Share-based payment arrangements [member] Share-based payment arrangements [member] Restricted Share Units Restricted Share Units (RSU) [Member] Restricted Share Units (RSU) [Member] Disclosure of terms and conditions of share-based payment arrangement [line items] Disclosure of terms and conditions of share-based payment arrangement [line items] Number of outstanding units, beginning of year Number of other equity instruments outstanding in share-based payment arrangement Number of units granted Number of other equity instruments granted in share-based payment arrangement Number of units vested and converted to common shares Number of outstanding units, end of year Disclosure of fair value measurement of equity [table] Disclosure of fair value measurement of equity [table] Long Term Investments Long Term Investments [Member] Long Term Investments [Member] Disclosure of fair value measurement of equity [line items] Disclosure of fair value measurement of equity [line items] Accumulated other comprehensive income (loss) Deferred tax expense (income) Operating loss carry-forwards Unused tax losses [member] Current assets and liabilities Derivatives Derivatives Related Temporary Differences [Member] Derivatives Related Temporary Differences [Member] Mining interests Property, Plant And Equipment Related Temporary Differences [Member] Property, Plant And Equipment Related Temporary Differences [Member] Other Other temporary differences [member] Deferred tax (liabilities)/assets Deferred income tax expense/(recovery) Deferred tax charged to equity Deferred tax relating to items credited (charged) directly to equity Disclosure of classes of share capital [table] Disclosure of classes of share capital [table] Major ordinary share transactions Major ordinary share transactions [member] Ordinary shares Ordinary shares [member] Preference shares Preference shares [member] Vesting1 [Axis] Vesting1 [Axis] Vesting1 [Axis] Vesting1 [Domain] Vesting1 [Domain] [Domain] for Vesting1 [Axis] Vesting 1 year from grant Vesting 2 years from grant Vesting 3 years from grant Tranche 3 [Member] Tranche 3 [Member] Incentive Plan Incentive Plan [Member] Incentive Plan [Member] Stock Options Stock Options [Member] Stock Options [Member] Deferred Share Unit Deferred Share Unit [Member] Deferred Share Unit [Member] Disclosure of classes of share capital [line items] Disclosure of classes of share capital [line items] Number of shares outstanding (in shares) Number of shares held in trust under the Company's Incentive Plan (in shares) Number of shares in entity held by entity or by its subsidiaries or associates Shares issued on exercise of stock options Number of options exercised (in shares) Shares issued under At-The-Market offering (in shares) Number Of Shares Issued, Issue Of Equity Number Of Shares Issued, Issue Of Equity Net proceeds from shares issued under the Company's At-The-Market offering Issue of equity Transaction costs Share issue related cost Share-based payments expense Expense from share-based payment transactions with employees Exercise price, share options granted (in Cdn.$per share) Exercise price, share options granted Term of options granted (in years) Share-based Compensation Arrangement By Share-based Payment Award Expiration Period1 Share-based Compensation Arrangement By Share-based Payment Award, Expiration Period1 Award vesting period (in years) Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Period2 Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Period2 Fair value of shares from share-based payment transactions Fair Value Of Shares From Share-Based Payment Transactions Fair Value Of Shares From Share-Based Payment Transactions Risk free annual interest rate Risk free interest rate, share options granted Expected option life (in years) Option life, share options granted Expected volatility Expected volatility, share options granted Dividend yield rate Expected dividend as percentage, share options granted Share-based payments expense, capitalized to mining interests Expense From Share-Based Payment Transactions With Employees, Capitalized To Mining Interests Expense From Share-Based Payment Transactions With Employees, Capitalized To Mining Interests Weighted average share price for share options exercised during period at date of exercise (in Cdn.$per share) Weighted average share price for share options in share-based payment arrangement exercised during period at date of exercise Measurement period Share Capital, Share Based Compensation, Measurement Period Share Capital, Share Based Compensation, Measurement Period Number of units granted (in shares) Award vesting percent Share-based Compensation By Share-based Payment Award, Other Equity Instruments Portion Vesting, Percent Share-based Compensation By Share-based Payment Award, Other Equity Instruments Portion Vesting, Percent Disclosure of fair value measurement of assets Disclosure of fair value measurement of assets [text block] Disclosure of fair value measurement of liabilities Disclosure of fair value measurement of liabilities [text block] Disclosure of liquidity risk Disclosure of liquidity risk [text block] Borrowing Installment [Axis] Borrowing Installment [Axis] Borrowing Installment [Axis] Borrowing Installment [Domain] Borrowing Installment [Domain] [Domain] for Borrowing Installment [Axis] Tranche 1 Tranche 2 Tranche 3 London Interbank Offered Rate LIBOR London Interbank Offered Rate LIBOR1 [Member] London Interbank Offered Rate LIBOR1 [Member] EURIBOR European Interbank Offered Rate EURIBOR [Member] European Interbank Offered Rate EURIBOR [Member] Accordion feature higher borrowing capacity Line Of Credit Facility, Accordion Feature, Higher Borrowing Capacity Option Line Of Credit Facility, Accordion Feature, Higher Borrowing Capacity Option Additional borrowing capacity Line Of Credit Facility, Additional Borrowing Capacity Line Of Credit Facility, Additional Borrowing Capacity Unused capacity commitment fee Line Of Credit Facility, Unused Capacity, Commitment Fee Percentage1 Line Of Credit Facility, Unused Capacity, Commitment Fee Percentage1 Borrowings maturity term Borrowings Maturity, Term Borrowings Maturity, Term Portion of convertible notes outstanding Debt Instrument, Covenant, Portion Of Convertible Notes Outstanding, Amount Debt Instrument, Covenant, Portion Of Convertible Notes Outstanding, Amount Repayments of lines of credit Repayment of credit facility Equipment loan facility, drawdowns net of transaction costs (Note 10) Proceeds from borrowings, classified as financing activities Mandatory reserve deposit payment coverage period Mandatory Reserve Deposit Payment Coverage Period Mandatory Reserve Deposit Payment Coverage Period Debt service reserve account Number of quarterly installment payments Borrowings, Number Of Quarterly Installment Payments Borrowings, Number Of Quarterly Installment Payments Commitment fee initial payment period Borrowings, Commitment Fee Initial Payment Period Borrowings, Commitment Fee Initial Payment Period Additional commitment fee percentage Borrowings, Additional Commitment Fee Percentage Borrowings, Additional Commitment Fee Percentage Investment [Table] Investment [Table] Investment [Line Items] Investment [Line Items] Disclosure of number and weighted average exercise prices of share options Disclosure of number and weighted average exercise prices of share options [text block] Disclosure of range of exercise prices of outstanding share options Disclosure of range of exercise prices of outstanding share options [text block] Disclosure of number and weighted average remaining contractual life of outstanding share options Disclosure of number and weighted average remaining contractual life of outstanding share options [text block] Disclosure of number and weighted average exercise prices of other equity instruments Disclosure of number and weighted average exercise prices of other equity instruments [text block] Earnings per share Earnings per share [text block] Fuel derivative contracts (Note 14) Convertible senior subordinated notes (Note 10) Classes of financial assets [axis] Classes of financial assets [axis] Financial assets, class [member] Financial assets, class [member] Long-term investments (Note 7) Equity investments [member] Interest rate swaps (Note 14) Levels of fair value hierarchy [axis] Levels of fair value hierarchy [axis] All levels of fair value hierarchy [member] All levels of fair value hierarchy [member] Level 1 Level 1 of fair value hierarchy [member] Level 2 Level 2 of fair value hierarchy [member] Level 3 Level 3 of fair value hierarchy [member] Measurement [axis] Measurement [axis] Aggregated measurement [member] Aggregated measurement [member] Recurring fair value measurement Recurring fair value measurement [member] Assets measured at fair value Liabilities measured at fair value Fekola Mine, Mali Otjikoto Mine, Namibia Masbate Mine, Philippines Libertad Mine, Nicaragua Limon Mine, Nicaragua Kiaka, Burkina Faso Ondundu, Namibia Gramalote, Colombia, net of impairment Cost, net of impairment Gross Carrying Amount, Net Of Impairment [Member] Gross Carrying Amount, Net Of Impairment [Member] Total property, plant and equipment and joint ventures accounted for using the equity method