Additional exercise price of per warrants in cash.

No definition available.

Name:	groy_AdditionalExercisePriceOfPerWarrantsInCash
Namespace Prefix:	groy_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Derivative liabilities recognized as of acquisition date.

+ References

No definition available.

+ Details

Name:	groy_DerivativeLiabilitiesRecognizedAsOfAcquisitionDate
Namespace Prefix:	groy_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Estimated forfeiture rate.

+ References

No definition available.

+ Details

Name:	groy_EstimatedAsPercentageShareOptionsForfeited
Namespace Prefix:	groy_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Exercise of warrants per common share.

+ References

No definition available.

+ Details

Name:	groy_ExerciseOfWarrantsPerCommonShare
Namespace Prefix:	groy_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Expected life.

+ References

No definition available.

+ Details

Name:	groy_ExpectedLifeOfWarrant
Namespace Prefix:	groy_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

Name:	groy_IfrsStatementLineItems
Namespace Prefix:	groy_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Warrants to purchase common shares outstanding.

+ References

No definition available.

+ Details

Name:	groy_WarrantsToPurchaseCommonSharesOutstanding
Namespace Prefix:	groy_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

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.

+ References

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

+ Details

Name:	ifrs-full_DescriptionOfExpectedVolatilityShareOptionsGranted
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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]]

+ References

+ Details

Name:	ifrs-full_DescriptionOfRiskFreeInterestRateShareOptionsGranted
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

+ Details

Name:	ifrs-full_ExpectedDividendAsPercentageShareOptionsGranted
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The gains (losses) resulting from change in the fair value of derivatives recognised in profit or loss. [Refer: Derivatives [member]]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2021-01-01
-Paragraph 85
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_85&doctype=Standard
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_GainsLossesOnChangeInFairValueOfDerivatives
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	ifrs-full_ComponentsOfEquityAxis=groy_ElyWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_UnobservableInputsAxis=ifrs-full_InterestRateMeasurementInputMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_UnobservableInputsAxis=ifrs-full_HistoricalVolatilityForSharesMeasurementInputMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_UnobservableInputsAxis=groy_ExpectedDividendYieldRateMeasurementInputMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_UnobservableInputsAxis=groy_EstimatedForfeitureRateMeasurementInputMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_BusinessCombinationsAxis=groy_AbitibiMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_HedgingInstrumentsAxis=groy_PutAndCallOptionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Derivative liabilities (Details Narrative) $ in Thousands	12 Months Ended
Derivative liabilities (Details Narrative) $ in Thousands	Sep. 30, 2022 USD ($) shares	Sep. 30, 2022 $ / shares shares	Sep. 30, 2021 USD ($)	Nov. 05, 2021 USD ($)
IfrsStatementLineItems [Line Items]
Fair value of put and call options on business combination				$ 691
Risk-free interest rate	1.39%
Expected volatility	47.99%
Expected dividend yield	0.14%
Fair value gain on change in fair value of derivative liabilities	$ 4,588		$ (1,511)
Ely Warrants [member]
IfrsStatementLineItems [Line Items]
Warrants to purchase common shares outstanding \| shares	8,849,251	8,849,251
Exercise of warrants per common share \| shares	0.2450
Additional exercise price of per warrants in cash \| $ / shares		$ 0.0001
Expected Life Of Warrant	7 months 20 days
Fair value gain on change in fair value of derivative liabilities	$ 3,999
Ely Warrants [member] \| Interest rate, measurement input [member]
IfrsStatementLineItems [Line Items]
Risk-free interest rate	3.75%
Ely Warrants [member] \| Historical volatility for shares, measurement input [member]
IfrsStatementLineItems [Line Items]
Expected volatility	40.00%
Ely Warrants [member] \| Expected dividend yield [member]
IfrsStatementLineItems [Line Items]
Expected dividend yield	0.00%
Ely Warrants [member] \| Estimated forfeiture rate [member]
IfrsStatementLineItems [Line Items]
Estimated forfeiture rate	0.00%
Abitibi [Member] \| Put and Call Options [Member]
IfrsStatementLineItems [Line Items]
Fair value of put and call options on business combination				$ 691
Fair value gain on change in fair value of derivative liabilities	$ 589