Name:	grpu_BorrowingsDeferredFinanceCostsGross
Namespace Prefix:	grpu_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The redemption spread in percent above the yield a non-callable Government of Canada Bond, trading at par, would carry if issued on the redemption date with maturity date of the debentures.

No definition available.

Name:	grpu_BorrowingsRedemptionSpreadBasisPoints
Namespace Prefix:	grpu_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	instant

Debt instrument settlement amount.

No definition available.

Name:	grpu_DebtInstrumentSettlementAmount
Namespace Prefix:	grpu_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

No definition available.

Name:	grpu_IFRSDebtInstrumentRedemptionPricePercentage
Namespace Prefix:	grpu_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	instant

The interest rate on borrowings. [Refer: Borrowings]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IFRS
-Number 7
-IssueDate 2023-01-01
-Paragraph 7
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2023-en-r&anchor=para_7&doctype=Standard
-URIDate 2023-03-23

Name:	ifrs-full_BorrowingsInterestRate
Namespace Prefix:	ifrs-full_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table.

No definition available.

Name:	ifrs-full_DisclosureOfDetailedInformationAboutBorrowingsLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The nominal or face amount of a financial instrument, used to calculate payments made on that instrument.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 112
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2023-03-23

Name:	ifrs-full_NotionalAmount
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

The cash outflow for repayments of current borrowings. [Refer: Current borrowings]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 7
-IssueDate 2023-01-01
-Paragraph 17
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2023-en-r&anchor=para_17&doctype=Standard
-URIDate 2023-03-23