Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Trading Arrangement: Trading Arrangement [Axis] Maximum Maximum [Member] Statistical Measurement [Domain] Statistical Measurement [Domain] Title of 12(b) Security Title of 12(b) Security Debt Securities, Available-for-Sale [Table] Debt Securities, Available-for-Sale [Table] Subsequent Event Subsequent Event [Member] Document Fiscal Year Focus Document Fiscal Year Focus Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items] Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items] Adjustment to Compensation, Amount Adjustment to Compensation Amount Segment Reporting [Abstract] Segment Reporting [Abstract] Credit Facility Credit Facility [Member] Represents a revolving credit facility agreement. Schedule of Fair Value, Assets Measured on Recurring Basis Fair Value, Assets Measured on Recurring Basis [Table Text Block] Common stock, $.01 par value, 200,000,000 shares authorized; and 84,673,027 and 84,499,692 shares outstanding, respectively Common Stock, Value, Issued Schedule of Debt Schedule of Long-Term Debt Instruments [Table Text Block] Line of Credit Line of Credit [Member] Restatement Determination Date Restatement Determination Date Effective income tax rate reconciliation, change in deferred tax assets valuation allowance, benefit Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount Highlander Silver Corp Highlander Silver Corp [Member] Highlander Silver Corp Amendment Flag Amendment Flag Shares acquired, average cost per share (in usd per shares) Shares Acquired, Average Cost Per Share Project [Axis] Project [Axis] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Relief Canyon Relief Canyon [Member] Relief Canyon Adjustments to comprehensive income, net of tax: Other Comprehensive Income (Loss), Net of Tax [Abstract] Interest and other expense Interest and other expense Interest and Other Expense The cost of borrowed funds accounted for as interest that was charged against earnings during the period and other expenses not previously classified. Effective income tax rate reconciliation, foreign income tax rate differential, benefit Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount Equity Method Investee Equity Method Investee [Member] Distributions to non-controlling interests Payments to Noncontrolling Interests Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Entity Address, State or Province Entity Address, State or Province PEO Total Compensation Amount PEO Total Compensation Amount Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Asset Acquisition [Axis] Asset Acquisition [Axis] Basic weighted average shares outstanding (in shares) Weighted-average shares for basic EPS (in shares) Weighted Average Number of Shares Outstanding, Basic Schedule of Stock-based Compensation Awards Share-Based Payment Arrangement, Activity [Table Text Block] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Number of reportable segments Number of Reportable Segments Total current liabilities Liabilities, Current Production taxes Production taxes Taxes, Miscellaneous Interest and other income Interest and other income Interest and Other Income EMEA EMEA [Member] Entity Address, City or Town Entity Address, City or Town Total equity awards granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Stock-based compensation Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Level 2 Fair Value, Inputs, Level 2 [Member] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Entree Resources Ltd. Entree Resources Ltd. [Member] Entree Resources Ltd. Other comprehensive income Other Comprehensive Income (Loss), Net of Tax Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Bear Creek Bear Creek [Member] Bear Creek Name of Property [Axis] Name of Property [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Other Other interest [Member] Represents mines, other than those elsewhere enumerated, in which the entity has royalty interests. Schedule of Long-Term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Royalty receivables Royalty Receivables The total amount due to the entity within one year of the balance sheet date relating to royalty contracts. Recent Adopted and Issued Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Other current liabilities Business Combination, Recognized Liability Assumed, Other Liability, Current Mercedes Mine Mercedes Mine [Member] Mercedes Mine Schedule of Reportable Segments for Assessing Performance Segment Reporting [Table Text Block] Non-controlling Interests Noncontrolling Interest [Member] Related and Nonrelated Parties [Axis] Related and Nonrelated Parties [Axis] Related party transaction, rate Related Party Transaction, Rate Income tax payable Increase (Decrease) in Income Taxes Payable Document Period End Date Document Period End Date Changes in assets and liabilities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Net cash used in investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation William Heissenbuttel [Member] William Heissenbuttel Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] STOCKHOLDERS' EQUITY Equity [Text Block] Security Exchange Name Security Exchange Name Interest rate, effective percentage Debt Instrument, Interest Rate, Effective Percentage Ilovica Ilovica [Member] Represents information pertaining to Ilovica Project, a Euromax's Ilovica gold-copper project located in southeast Macedonia. Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Related party transaction, term Related Party Transaction, Term Related Party Transaction, Term EARNINGS PER SHARE ("EPS") Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Proceeds from the sale of marketable securities Proceeds from Sale and Maturity of Marketable Securities Net income per share attributable to Royal Gold common stockholders: Earnings Per Share [Abstract] Earnings Per Share [Abstract] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Document Fiscal Period Focus Document Fiscal Period Focus Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Hod Maden Project Development, Additional Advance Hod Maden Project Development, Additional Advance [Member] Hod Maden Project Development, Additional Advance Total liabilities Liabilities Trading Symbol Trading Symbol Total costs and expenses Segment Reporting, Costs And Expenses Segment Reporting, Costs And Expenses Geographical [Domain] Geographical [Domain] Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Schedule of Stream and Royalty Interests Schedule of Stream and Royalty Interests in Mineral Properties [Table Text Block] Tabular disclosure of stream and royalty interests in mineral properties of the entity, including gross amount, accumulated depletion and net amount as of the balance sheet date. Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Total allocated purchase price Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Consideration Transferred Schedule of Unrecognized Compensation Expense Share-Based Payment Arrangement, Nonvested Award, Cost [Table Text Block] Income tax payable Accrued Income Taxes, Current Schedule of Business Combination, Recognized Asset Acquired and Liability Assumed Business Combination, Recognized Asset Acquired and Liability Assumed [Table Text Block] Company Selected Measure Name Company Selected Measure Name Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Total exploration stage interests Exploration Stage Stream And Royalty Interests [Member] Represents the exploration stage stream and royalty interests of the entity. Realized gain on available-for-sale debt securities OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax Conversion ratio Investment, Convertible, Conversion Ratio Investment, Convertible, Conversion Ratio Principal Long-Term Debt, Gross Deposit Liability [Table] Deposit Liability [Table] Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Credit Facility [Domain] Credit Facility [Domain] Equity ownership percentage Equity Ownership, Excluding Consolidated Entity and Equity Method Investee, Percentage Cash flows from operating activities: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Compensation Amount Outstanding Recovery Compensation Amount Dividends payable Dividends Payable, Current Individual: Individual [Axis] Diluted weighted average shares outstanding (in shares) Weighted-average shares for diluted EPS (in shares) Weighted Average Number of Shares Outstanding, Diluted Disaggregation of Revenue Disaggregation of Revenue [Line Items] Entity Emerging Growth Company Entity Emerging Growth Company Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Hod Maden Project Development, Initial Advance Hod Maden Project Development, Initial Advance [Member] Hod Maden Project Development, Initial Advance Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Royalty revenue Royalty Interests [Member] Represents information pertaining to the Royalty Interest segment, a reportable segment of the company. Segment gross profit Total segment gross profit Gross Profit Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Effect of other dilutive securities (in shares) Weighted Average Number of Shares Outstanding, Diluted, Adjustment Award Timing Predetermined Award Timing Predetermined [Flag] Debt Securities, Available-for-Sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Project [Domain] Project [Domain] Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Level 1 Fair Value, Inputs, Level 1 [Member] Hod Maden Interest Hod Maden Interest [Member] Hod Maden Interest Royalty interest Royalty Interest [Member] Represents information pertaining to the Royalty Interest segment, a reportable segment of the company. Effective tax rate Effective Income Tax Rate Reconciliation, Percent Consideration payable Asset Acquisition, Contingent Consideration, Liability All Executive Categories All Executive Categories [Member] Stock repurchase Stock Repurchased and Retired During Period, Value Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Repayment of debt Repayments of Long-Term Lines of Credit Gain on sale of marketable securities Gain on sale of marketable securities Marketable Security, Realized Gain (Loss) Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Asset Acquisition [Domain] Asset Acquisition [Domain] Acquisition of stream and royalty interests Acquisition of stream and royalty interests Payments to Acquire Mineral Rights Accumulated Depletion Mineral Properties, Accumulated Depletion Net smelter return, unsecured percentage Asset Acquisition, Net Smelter Return, Unsecured, Percentage Asset Acquisition, Net Smelter Return, Unsecured, Percentage Bear Creek Convertible Debenture Bear Creek Convertible Debenture [Member] Bear Creek Convertible Debenture Income tax receivable Increase (Decrease) in Income Taxes Receivable Schedule of the Effects of Dilutive Securities on Diluted EPS Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] SEGMENT INFORMATION Segment Reporting [Text Block] MARKETABLE SECURITIES Investment in Debt and Equity Securities and Other Trading Assets [Text Block] Minimum Minimum [Member] Outstanding amount Long-Term Line of Credit Common stock dividends Payments of Ordinary Dividends, Common Stock Expiration Date Trading Arrangement Expiration Date Schedule of Disaggregated Revenue Disaggregation of Revenue [Table Text Block] LIABILITIES Liabilities [Abstract] Proceeds from debt settlement Proceeds From Debt Settlement Proceeds From Debt Settlement Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Total equity Balance Balance Equity, Including Portion Attributable to Noncontrolling Interest Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Business Combination [Line Items] Business Combination [Line Items] Dividends declared Dividends, Common Stock Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Common stock, shares authorized (in shares) Common Stock, Shares Authorized Royalty receivables Business Combination, Recognized Asset Acquired, Receivable, Current Exercise Price Award Exercise Price Silver Silver [Member] Represents information pertaining to silver. Cash flows from investing activities: Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Related Party Transaction [Axis] Related Party Transaction [Axis] Share repurchase program, authorized amount Share Repurchase Program, Authorized, Amount Total allocated purchase price Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less), and Goodwill, Less Noncontrolling Interest Unrecognized compensation expense Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Document Quarterly Report Document Quarterly Report Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Segments [Domain] Segments [Domain] Schedule of Geographical Distribution of Long-lived Assets Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Long-Lived Asset [Table Text Block] Cortez Legacy Zone Cortez Legacy Zone [Member] Cortez Legacy Zone DEBT Debt Disclosure [Text Block] Repayment of debt Repayments of Long-Term Debt Sandstorm and Horizon Sandstorm And Horizon [Member] Sandstorm And Horizon Schedule of Marketable Securities Marketable Securities [Table Text Block] Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Equity method investment (Note 4) Equity method investment Equity Method Investments Business Combination [Table] Business Combination [Table] ACQUISITION OF SANDSTORM GOLD AND HORIZON COPPER Mergers, Acquisitions and Dispositions Disclosures [Text Block] Equity Component [Domain] Equity Component [Domain] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Streams Exploration Stage Stream Interests [Member] Represents exploration stage stream interest of entity. Total costs and expenses Costs and Expenses Adoption Date Trading Arrangement Adoption Date STREAM AND ROYALTY INTERESTS, NET STREAM AND ROYALTY INTERESTS, NET No definition available. Cash calls for Hod Maden equity method investment Payments to acquire investments Payments to Acquire Equity Method Investments Counterparty Name [Domain] Counterparty Name [Domain] Equity method investment Equity method investment, adjusted Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Equity Method Investment, Noncurrent Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Equity Method Investment, Noncurrent Total Royal Gold stockholders’ equity Equity, Attributable to Parent Other assets Business Combination, Recognized Asset Acquired, Other Asset, Noncurrent Stream and royalty interests Stream and royalty interests acquired, measurement period adjustments Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Mineral Properties, Noncurrent Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Mineral Properties, Noncurrent Pueblo Viejo Pueblo Viejo [Member] Represents Pueblo Viejo, a mine located in the Dominican Republic. ASSETS Assets [Abstract] Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Accounting Policies [Abstract] Accounting Policies [Abstract] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Kansanshi Kansanshi [Member] Kansanshi Deposit Liability [Line Items] Deposit Liability [Line Items] Insider Trading Policies and Procedures [Line Items] Other Proceeds from (Payment for) Other Financing Activity Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Performance stock Performance Shares [Member] Accordion feature, higher borrowing capacity option Line of Credit Facility, Accordion Feature, Higher Borrowing Capacity Option Line of Credit Facility, Accordion Feature, Higher Borrowing Capacity Option Americas Gold And Silver Corporation Americas Gold And Silver Corporation [Member] Americas Gold And Silver Corporation Prepaid expenses and other Prepaid Expense and Other Assets, Current Deferred tax benefit Deferred Income Tax Expense (Benefit) Business Combination [Domain] Business Combination [Domain] Long Lived Assets and Pre-Tax Income by Geographical Information Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items] COMMITMENTS AND CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Marketable securities Business Combination, Recognized Asset Acquired, Marketable Securities, Noncurrent Business Combination, Recognized Asset Acquired, Marketable Securities, Noncurrent Entity Central Index Key Entity Central Index Key Income tax receivable Business Combination, Recognized Asset Acquired, Income Tax Receivable, Current Business Combination, Recognized Asset Acquired, Income Tax Receivable, Current All Adjustments to Compensation All Adjustments to Compensation [Member] Name of Property [Domain] Name of Property [Domain] Business Combination [Axis] Business Combination [Axis] Equity [Abstract] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Other Other [Member] Other Net cash provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Income Statement [Abstract] Income Statement [Abstract] Document Transition Report Document Transition Report Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Investment, Name [Axis] Investment, Name [Axis] Schedule of Components of Income Tax Expense Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate City Area Code City Area Code Gold Gold [Member] Restricted stock Restricted Stock [Member] Deferred tax liabilities Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Deferred Tax Liability Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Deferred Tax Liability Accumulated Other Comprehensive Income AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] Schedule of Revenue by Reportable Segment Geographically Distributed Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue [Table Text Block] Name Forgone Recovery, Individual Name Weighted- average vesting period (years) Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Security Milestone Security Milestone [Member] Security Milestone Statement Statement [Line Items] Marketable securities (Note 5) Marketable Securities, Noncurrent Total assets Assets Entity [Domain] Entity [Domain] Business Combination [Abstract] Gain on sale of marketable securities Equity Securities, FV-NI, Realized Gain (Loss) Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Convertible Debt Convertible Debt [Member] Net payments from issuance of common stock Payments For Issuance Of Common Stock, Net Payments For Issuance Of Common Stock, Net STOCK-BASED COMPENSATION Share-Based Payment Arrangement [Text Block] PEO PEO [Member] Balance (in shares) Balance (in shares) Shares outstanding (in shares) Shares, Outstanding Total stock-based compensation expense Share-Based Payment Arrangement, Expense Accordion feature, increase limit Line of Credit Facility, Accordion Feature, Increase Limit Line of Credit Facility, Accordion Feature, Increase Limit Stock repurchase (in shares) Stock repurchase (in shares) Stock Repurchased and Retired During Period, Shares Copper Copper [Member] Represents information pertaining to copper. Other liabilities Other Liabilities, Noncurrent Asset Acquisition, Contingent Consideration, Type [Axis] Asset Acquisition, Contingent Consideration, Type [Axis] Asset Acquisition, Contingent Consideration, Type Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Royalties Exploration Stage Royalty Interests [Member] Represents the exploration stage royalty interest of the entity. Accounts payable Business Combination, Recognized Liability Assumed, Accounts Payable, Current Subsequent Event Type [Domain] Subsequent Event Type [Domain] Net smelter return, royality percentage Net Smelter Return, Royality Percentage Net Smelter Return, Royality Percentage Accumulated Earnings Retained Earnings [Member] Revolving Credit Facility Revolving Credit Facility [Member] Cash Business Combination, Recognized Asset Acquired, Cash and Cash Equivalent Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Increase (Decrease) in Stockholders' Equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Streams Development Stage Stream Interests [Member] Represents the development stage steam interest of the entity. Diluted earnings per share (in dollars per share) Diluted EPS (in dollars per share) Earnings Per Share, Diluted Entity Current Reporting Status Entity Current Reporting Status Net cash used in financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Total Shareholder Return Amount Total Shareholder Return Amount Prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Cortez CC Zone Cortez CC Zone [Member] Cortez CC Zone Adjustments to reconcile net income to net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Share-Based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Cash flows from financing activities: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Revenue (Note 9) Total revenue Revenue Revenue from Contract with Customer, Excluding Assessed Tax Line of credit facility, remaining borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Total production stage interests Production Stage Stream And Royalty Interests [Member] Represents the production stage stream and royalty interests of the entity. Non-controlling interests Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Underlying Securities Award Underlying Securities Amount Comprehensive income attributable to non-controlling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest MOUNT MILLIGAN DEFERRED LIABILITY REVENUE Revenue from Contract with Customer [Text Block] Artmin Artmin [Member] Artmin Other Payment for (Proceeds from) Other Investing Activity Stream inventory Increase (Decrease) in Inventories Stream interest Stream Interest [Member] Represents information pertaining to the Stream Interest segment, a reportable segment of the company. Andacollo Andacollo [Member] Represents Andacollo, a mine in which the entity has royalty interests. Equity Method Investment [Table] Equity Method Investment [Table] Stream and royalty interests Business Combination, Recognized Asset Acquired, Mineral Properties, Noncurrent Business Combination, Recognized Asset Acquired, Mineral Properties, Noncurrent Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] All Trading Arrangements All Trading Arrangements [Member] Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Operating income Operating Income (Loss) Current Fiscal Year End Date Current Fiscal Year End Date Investment owned, balance (in shares) Investment Owned, Balance, Shares Corani Project Corani Project [Member] Corani Project Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Related Party Transaction [Domain] Related Party Transaction [Domain] Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Cash dividends declared per common share (in dollars per share) Common Stock, Dividends, Per Share, Declared Entity File Number Entity File Number Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Stock-based compensation and related share issuances Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture Distributions to non-controlling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Common stock, shares, issued (in shares) Common Stock, Shares, Issued Measure: Measure [Axis] EQUITY METHOD INVESTMENT Equity Method Investments and Joint Ventures Disclosure [Text Block] Warintza Project Stream and Royalty Warintza Project Stream and Royalty [Member] Warintza Project Stream and Royalty Cost of sales (excludes depreciation, depletion and amortization) Cost of sales Cost of Goods and Service, Excluding Depreciation, Depletion, and Amortization Equity Components [Axis] Equity Components [Axis] Royalty receivables Increase (Decrease) in Accounts Receivable Product and Service [Domain] Product and Service [Domain] Related Party Related Party [Member] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Entity Interactive Data Current Entity Interactive Data Current Net income attributable to non-controlling interests Net Income (Loss) Attributable to Noncontrolling Interest Deferred tax liabilities Deferred Income Tax Liabilities, Net Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Entity Small Business Entity Small Business Comprehensive income attributable to Royal Gold stockholders Comprehensive Income (Loss), Net of Tax, Attributable to Parent Effective income tax rate reconciliation, recoverable tax basis, foreign, amount Effective Income Tax Rate Reconciliation, Recoverable Tax Basis, Foreign, Amount Effective Income Tax Rate Reconciliation, Recoverable Tax Basis, Foreign, Amount Termination Date Trading Arrangement Termination Date Fair Value Disclosure of Asset and Liability Not Measured at Fair Value [Table] Fair Value, Recurring and Nonrecurring [Table] Mount Milligan Mt. Milligan [Member] Represents Mount Milligan, a mine in which the entity has royalty interests. Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Other current liabilities Other Liabilities, Current Total marketable securities Marketable Securities Other assets Other Assets, Noncurrent Document Type Document Type Zinc Zinc [Member] Zinc Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value as of Grant Date Award Grant Date Fair Value Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Arrangement Duration Trading Arrangement Duration Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Local Phone Number Local Phone Number Mount Milligan deferred liability (Note 7) Value of cash consideration Contract with Customer, Liability, Noncurrent Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name OPERATIONS, SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING STANDARDS Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Commitments and contingencies (Note 15) Commitments and Contingencies Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Executive Category: Executive Category [Axis] Counterparty Name [Axis] Counterparty Name [Axis] Costs and expenses Operating Costs and Expenses [Abstract] Other Commitments [Table] Other Commitments [Table] Australia Pacific AUSTRALIA All Award Types Award Type [Domain] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount FAIR VALUE MEASUREMENTS Fair Value Disclosures [Text Block] Level 3 Fair Value, Inputs, Level 3 [Member] Net smelter return (NSR) percentage Asset Acquisition, Net Smelter Return, Percentage Asset Acquisition, Net Smelter Return, Percentage Net smelter return, incremental percentage Asset Acquisition, Net Smelter Return, Incremental Increase, Percentage Asset Acquisition, Net Smelter Return, Incremental Increase, Percentage PEO Name PEO Name Geographical [Axis] Geographical [Axis] Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Legal Entity [Axis] Legal Entity [Axis] Equity method investment Business Combination, Recognized Asset Acquired, Equity Method Investment, Noncurrent Business Combination, Recognized Asset Acquired, Equity Method Investment, Noncurrent Interest expense, debt Interest Expense, Debt Other Commitments [Line Items] Other Commitments [Line Items] Hod Maden Project Development, Total Advance Hod Maden Project Development, Total Advance [Member] Hod Maden Project Development, Total Advance Cash and equivalents at beginning of period Cash and equivalents at end of period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Streams Production Stage Stream Interests [Member] Represents the production stage stream interests of the entity. Accounts payable Increase (Decrease) in Accounts Payable Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Non-NEOs Non-NEOs [Member] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Debt Instrument [Axis] Debt Instrument [Axis] Equity method investment, ownership percentage Equity Method Investment, Ownership Percentage Other liabilities Business Combination, Recognized Liability Assumed, Other Liability, Noncurrent Non-cash employee stock compensation expense Share-Based Payment Arrangement, Noncash Expense Sandstorm converted options exercises (in shares) Stock Issued During Period, Shares, Conversion of Convertible Securities Conditional funding from acquisition Asset Acquisition, Consideration Transferred, Contingent Consideration Investment, Name [Domain] Investment, Name [Domain] Long-Term Debt, Type [Domain] Long-Term Debt, Type [Domain] Basic earnings per share (in dollars per share) Basic EPS (in dollars per share) Earnings Per Share, Basic Stock repurchase Total consideration of repurchased shares Payments for Repurchase of Common Stock Total current assets Assets, Current Statistical Measurement [Axis] Statistical Measurement [Axis] Insider Trading Arrangements [Line Items] Debt (Note 6) Total Long-Term Debt, Excluding Current Maturities Award Type Award Type [Axis] Stream revenue Stream interest Stream Interests [Member] Represents information pertaining to the Stream Interest segment, a reportable segment of the company. Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Accumulated earnings Retained Earnings (Accumulated Deficit) Product and Service [Axis] Product and Service [Axis] Marketable securities Available-for-sale equity securities Equity Securities, FV-NI Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Common Shares Common Stock [Member] Available-for-sale debt securities Debt Securities, Available-for-Sale Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover [Abstract] Cover [Abstract] South and Central America South And Central Amercia [Member] South And Central Amercia Gain on settlement of Relief Canyon fixed obligation Gain on settlement of Relief Canyon fixed obligation Gain (Loss) On Settlement Of Fixed Obligation Gain (Loss) On Settlement Of Fixed Obligation Measurement period adjustments Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments [Abstract] Equity Awards Adjustments Equity Awards Adjustments [Member] Total liabilities and equity Liabilities and Equity Employee Stock Option Share-Based Payment Arrangement, Option [Member] Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Table] Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Table] Royalties Production Stage Royalty Interests [Member] Represents the production stage royalty interest of the entity. Non-controlling interests Equity, Attributable to Noncontrolling Interest Segments [Axis] Segments [Axis] Other liabilities Increase (Decrease) in Other Operating Liabilities Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Related and Nonrelated Parties [Domain] Related and Nonrelated Parties [Domain] Cost Mineral Properties, Gross Tabular List, Table Tabular List [Table Text Block] Additional paid-in capital Additional Paid in Capital Schedule of Recognized Stock-based Compensation Expense Share-Based Payment Arrangement, Cost by Plan [Table Text Block] Income tax receivable Income Taxes Receivable, Current Name Awards Close in Time to MNPI Disclosures, Individual Name EQUITY Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] General and administrative General and administrative expenses General and Administrative Expense Sandstorm converted options exercises Stock Issued During Period, Value, Conversion of Convertible Securities Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Preferred stock, $.01 par value, 10,000,000 shares authorized; and 0 shares issued Preferred Stock, Value, Issued Adjustment to Compensation: Adjustment to Compensation [Axis] STREAM AND ROYALTY INTERESTS, NET Stream and Royalty Interests in Mineral Properties Disclosures [Text Block] The entire disclosure for stream and royalty interests, net in mineral properties. Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Settled debt obligations Extinguishment of Debt, Amount Credit Facility [Axis] Credit Facility [Axis] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Stream and royalty interests, net (Note 3) Net Total stream and royalty interests, net Mineral Properties, Net Name Measure Name INCOME TAXES Income Tax Disclosure [Text Block] Accounts payable Accounts Payable, Current Pay vs Performance Disclosure [Line Items] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Other Other Noncash Income (Expense) Long-term debt disclosure Debt Instrument [Line Items] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Additional Paid-In Capital Additional Paid-in Capital [Member] Entity Filer Category Entity Filer Category Name Trading Arrangement, Individual Name Cash and equivalents Cash and Cash Equivalent Company Selected Measure Amount Company Selected Measure Amount Asset Acquisition, Contingent Consideration, Type [Domain] Asset Acquisition, Contingent Consideration, Type [Domain] Asset Acquisition, Contingent Consideration, Type [Domain] Delivery obligations, ounces Asset Acquisition, Gold Deliverable, Obligation Cost Support Agreement, Gold Ounces, Delivered To Settle Obligation Schedule of Reconciliation of Segment Gross Profit to Consolidated Income (Loss) Segment Reporting, Reconciliation of Profit (Loss) by Segment to Consolidated [Table Text Block] Fair value changes in equity securities Fair value changes in equity securities Fair value changes in equity securities Equity Securities, FV-NI, Unrealized Gain (Loss) Investments, Debt and Equity Securities [Abstract] Equity Method Investments and Joint Ventures [Abstract] Depreciation, depletion and amortization Depreciation, Depletion and Amortization Stream inventory Inventory, Gross Average sale price determination period Spot Rate Forward Contracts Average Sale Price Determination Period Represents the period of consecutive trading days under the spot rate forward contract in which the sale price is determined on the daily average spot price. Entity Address, Address Line Two Entity Address, Address Line Two Stock-based compensation and related share issuances (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Net income Net income and comprehensive income Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Table] Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Table] Earn out basis if all goals are met (as a percent) Share Based Compensation Arrangement, by Share Based Payment Award, Percentage of Interim Earn Out as Basis for Vesting Three Percentage of third interim earn out which is a basis for vesting. Non-PEO NEO Non-PEO NEO [Member] Entity Address, Address Line One Entity Address, Address Line One North America North America [Member] Total development stage interests Development Stage Stream And Royalty Interests [Member] Represents the development stage stream and royalty interests of the entity. Income tax expense (Note 12) Income tax expense Income Tax Expense (Benefit) Value of consideration, nonmonetary amount, gold Contract With Customer, Liability, Nonmonetary Amount, Gold Represents the quantity of gold produced or delivered under the terms of the agreement. Award Timing Method Award Timing Method [Text Block] Summary of Significant Accounting Policies Consolidation, Policy [Policy Text Block] Net (decrease) increase in cash and equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Deferred tax liabilities Business Combination, Recognized Liability Assumed, Deferred Tax Liability Net income attributable to Royal Gold common stockholders Net income attributable to Royal Gold common stockholders Net Income (Loss) Attributable to Parent Long-Term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Debt Issuance Costs Unamortized Debt Issuance Expense Statement [Table] Statement [Table] Restatement Determination Date: Restatement Determination Date [Axis] Net proceeds from Sandstorm option exercises Proceeds from Stock Options Exercised Accounts payable Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Accounts Payable, Current Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Accounts Payable, Current Equity method investment, ownership percentage, adjustment Equity Method Investment, Ownership Percentage, Adjustment Equity Method Investment, Ownership Percentage, Adjustment Depletion Depletion Royalties Development Stage Royalty Interests [Member] Represents the development stage royalty interest of the entity. Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Prepaid expenses and other Business Combination, Recognized Asset Acquired, Prepaid Expense and Other Asset, Current