Name:	groy_AdvisoryAndConsultingFees
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Business acquisition shares issued or issuable.

No definition available.

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Business acquisition transaction costs and change of control payments.

No definition available.

Name:	groy_BusinessAcquisitionTransactionCostsAndChangeOfControlPayments
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Consideration paid.

No definition available.

Name:	groy_ConsiderationPaid
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Consulting fees.

No definition available.

Name:	groy_ConsultingFees
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Period Type:	duration

- References

No definition available.

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Expected life.

No definition available.

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Balance Type:	na
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Estimated forfeiture rate.

No definition available.

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Balance Type:	na
Period Type:	duration

- References

No definition available.

Name:	groy_IfrsStatementLineItems
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Balance Type:	na
Period Type:	duration

Net profit interest royalty percentage.

No definition available.

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Period Type:	instant

Net smelter return royalty percentage.

No definition available.

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Balance Type:	na
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Number of Options Issued.

No definition available.

Name:	groy_NumberOfOptionsIssued
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Balance Type:	na
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Number of royalties acquired.

No definition available.

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Balance Type:	na
Period Type:	duration

Number of shares issued on acquisition.

No definition available.

Name:	groy_NumberOfSharesIssuedOnAcquisition
Namespace Prefix:	groy_
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Balance Type:	na
Period Type:	duration

Number of warrants issued to purchase shares.

No definition available.

Name:	groy_NumberOfWarrantsIssuedToPurchaseShares
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Balance Type:	na
Period Type:	duration

Payment from cash consideration.

No definition available.

Name:	groy_PaymentFromCashConsideration
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Share price.

No definition available.

Name:	groy_SharePricePerShare
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Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

Transaction costs.

No definition available.

Name:	groy_TransactionCosts
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Warrants deemed to be exchanged for Shares.

No definition available.

Name:	groy_WarrantsDeemedToBeExchangedForShares
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

The fair value, at acquisition date, of the consideration transferred in a business combination. [Refer: Business combinations [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph B64
-Subparagraph f
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_f&doctype=Appendix&subtype=B
-URIDate 2021-03-24

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The fair value, at acquisition date, of cash transferred as consideration in a business combination. [Refer: Business combinations [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph B64
-Subparagraph f
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-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_f_i&doctype=Appendix&subtype=B
-URIDate 2021-03-24

Name:	ifrs-full_CashTransferred
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The amount of consideration paid or received in respect of both obtaining and losing control of subsidiaries or other businesses. [Refer: Subsidiaries [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 7
-IssueDate 2021-01-01
-Paragraph 40
-Subparagraph a
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-URIDate 2021-03-24

Name:	ifrs-full_ConsiderationPaidReceived
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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

The expected volatility of the share price used to calculate the fair value of the share options granted. Expected volatility is a measure of the amount by which a price is expected to fluctuate during a period. The measure of volatility used in option pricing models is the annualised standard deviation of the continuously compounded rates of return on the share over a period of time.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2021-01-01
-Paragraph 47
-Subparagraph a
-Clause i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_47_a_i&doctype=Standard
-URIDate 2021-03-24

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The implied yield currently available on zero-coupon government issues of the country in whose currency the exercise price for share options granted is expressed, with a remaining term equal to the expected term of the option being valued (based on the option's remaining contractual life and taking into account the effects of expected early exercise). [Refer: Government [member]]

Name:	ifrs-full_DescriptionOfRiskFreeInterestRateShareOptionsGranted
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The exercise price of share options granted.

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Data Type:	num:perShareItemType
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Period Type:	duration

The percentage of an expected dividend used to calculate the fair value of share options granted.

Name:	ifrs-full_ExpectedDividendAsPercentageShareOptionsGranted
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Balance Type:	na
Period Type:	duration

The amount of expense from share-based payment transactions with employees. [Refer: Expense from share-based payment transactions]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2021-01-01
-Paragraph 112
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-URIDate 2021-03-24

Name:	ifrs-full_ExpenseFromSharebasedPaymentTransactionsWithEmployees
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The number of other equity instruments (ie other than share options) exercisable in a share-based payment arrangement.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IFRS
-Number 2
-IssueDate 2021-01-01
-Paragraph 45
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_45&doctype=Standard
-URIDate 2021-03-24

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Data Type:	xbrli:decimalItemType
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Period Type:	instant

The number of share options outstanding in a share-based payment arrangement.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2021-01-01
-Paragraph 45
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_45_d&doctype=Standard
-URIDate 2021-03-24

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2021-01-01
-Paragraph 45
-Subparagraph b
-Clause i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_45_b_i&doctype=Standard
-URIDate 2021-03-24

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2021-01-01
-Paragraph 45
-Subparagraph b
-Clause vi
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_45_b_vi&doctype=Standard
-URIDate 2021-03-24

Name:	ifrs-full_NumberOfOutstandingShareOptions
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Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

The number of shares issued by the entity.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2021-01-01
-Paragraph 106
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_106_d&doctype=Standard
-URIDate 2021-03-24

Name:	ifrs-full_NumberOfSharesIssued
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The profit (loss) of the acquiree, since the acquisition date, included in the consolidated statement of comprehensive income. [Refer: Profit (loss)]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph B64
-Subparagraph q
-Clause i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_q_i&doctype=Appendix&subtype=B
-URIDate 2021-03-24

Name:	ifrs-full_ProfitLossOfAcquiree
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The profit (loss) of the combined entity as though the acquisition date for all business combinations that occurred during the year had been as of the beginning of the annual reporting period. [Refer: Business combinations [member]; Profit (loss)]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph B64
-Subparagraph q
-Clause ii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_q_ii&doctype=Appendix&subtype=B
-URIDate 2021-03-24

Name:	ifrs-full_ProfitLossOfCombinedEntity
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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

The amount of revenue of the acquiree since the acquisition date included in the consolidated statement of comprehensive income. [Refer: Revenue]

Name:	ifrs-full_RevenueOfAcquiree
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Period Type:	duration

The revenue of the combined entity as though the acquisition date for all business combinations that occurred during the year had been as of the beginning of the annual reporting period. [Refer: Business combinations [member]; Revenue]

Name:	ifrs-full_RevenueOfCombinedEntity
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
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Period Type:	duration

The weighted average share price used as input to the option pricing model to calculate the fair value of share options granted. [Refer: Option pricing model [member]; Weighted average [member]]

Name:	ifrs-full_WeightedAverageSharePriceShareOptionsGranted2019
Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

Name:	ifrs-full_BusinessCombinationsAxis=groy_ElyMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	ifrs-full_BusinessCombinationsAxis=groy_GoldenValleyAndAbitibiMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=groy_CanadianMalarticPropertyMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	ifrs-full_TypesOfContractsAxis=groy_RoyaltyOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	ifrs-full_TypesOfContractsAxis=groy_RoyaltyTwoMember
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Data Type:	na
Balance Type:
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Name:	ifrs-full_TypesOfContractsAxis=groy_RoyaltyThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=groy_CheechooProjectMember
Namespace Prefix:
Data Type:	na
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Name:	ifrs-full_RangeAxis=ifrs-full_BottomOfRangeMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	ifrs-full_RangeAxis=ifrs-full_TopOfRangeMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	ifrs-full_BusinessCombinationsAxis=groy_GoldenValleyMinesAndRoyaltiesLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	ifrs-full_BusinessCombinationsAxis=groy_AbitibiRoyaltiesIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	ifrs-full_ComponentsOfEquityAxis=groy_GRCSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	ifrs-full_ComponentsOfEquityAxis=groy_ElyWarrantMember
Namespace Prefix:
Data Type:	na
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