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

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 redemption period of debentures, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. This represents the option Granite has to redeem the debentures at par plus any accrued and unpaid interest within 30 days of the maturity date.

No definition available.

Name:	grpu_RedemptionPeriodOfDebentures
Namespace Prefix:	grpu_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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