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

The amount of undrawn borrowing facilities that may be available for future operating activities and to settle capital commitments. [Refer: Capital commitments]

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 7
-IssueDate 2021-01-01
-Paragraph 50
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_50_a&doctype=Standard
-URIDate 2021-03-24

Name:	ifrs-full_UndrawnBorrowingFacilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

No definition available.

Name:	su_IfrsLineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	su_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Represents the portion of line of credit facilities that are assigned for specific purposes.

No definition available.

Name:	su_LineOfCreditFacilitiesAssignedForSpecificPurposes
Namespace Prefix:	su_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The amount of undrawn borrowing facilities for liquidity purposes that may be available for future operating activities and to settle capital commitments.

No definition available.

Name:	su_UnusedBorrowingFacilitiesForLiquidityPurposes
Namespace Prefix:	su_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Name:	ifrs-full_BorrowingsByNameAxis=su_FullyRevolvingAndExpiresIn2025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_BorrowingsByNameAxis=su_FullyRevolvingAndExpiresIn2024Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_BorrowingsByNameAxis=su_CreditFacilitiesThatCanBeTerminatedAtAnyTimeByLenderMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_BorrowingsByNameAxis=su_CreditFacilitiesSupportingOutstandingCommercialPaperMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: