Goodwill and Other Intangible Assets - Changes (Details) - CAD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Other Intangibles
Beginning balance	$ 694	$ 631
Additions	22	140
Amortization	(80)	(57)
Reclassified to assets held for sale		(20)
Ending balance	636	694
Total
Beginning balance	3,586	3,523
Additions	22	140
Amortization	(80)	(57)
Reclassified to assets held for sale		(20)
Ending balance	3,528	3,586
Oil Sands
Goodwill
Beginning balance	2,752	2,752
Additions
Ending balance	2,752	2,752
Refining and Marketing
Goodwill
Beginning balance	140	140
Additions
Ending balance	$ 140	$ 140

The amount of additional goodwill recognised, except goodwill included in a disposal group that, on acquisition, meets the criteria to be classified as held for sale in accordance with IFRS 5. [Refer: Goodwill; Disposal groups classified as held for sale [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2023-01-01
-Paragraph B67
-Subparagraph d
-Clause ii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2023-en-r&anchor=para_B67_d_ii&doctype=Appendix&subtype=B
-URIDate 2023-03-23

+ Details

Name:	ifrs-full_AdditionalRecognitionGoodwill
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of additions to intangible assets other than goodwill, other than those acquired through business combinations. [Refer: Business combinations [member]; Intangible assets other than goodwill]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 38
-IssueDate 2023-01-01
-Paragraph 118
-Subparagraph e
-Clause i
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=38&code=ifrs-tx-2023-en-r&anchor=para_118_e_i&doctype=Standard
-URIDate 2023-03-23

+ Details

Name:	ifrs-full_AdditionsOtherThanThroughBusinessCombinationsIntangibleAssetsOtherThanGoodwill
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of amortisation of intangible assets other than goodwill. [Refer: Depreciation and amortisation expense; Intangible assets other than goodwill]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 38
-IssueDate 2023-01-01
-Paragraph 118
-Subparagraph e
-Clause vi
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=38&code=ifrs-tx-2023-en-r&anchor=para_118_e_vi&doctype=Standard
-URIDate 2023-03-23

+ Details

Name:	ifrs-full_AmortisationIntangibleAssetsOtherThanGoodwill
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

The decrease in intangible assets and goodwill resulting from classification as held for sale or inclusion in a disposal group classified as held for sale. [Refer: Disposal groups classified as held for sale [member]; Intangible assets and goodwill]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 38
-IssueDate 2023-01-01
-Paragraph 118
-Subparagraph e
-Clause ii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=38&code=ifrs-tx-2023-en-r&anchor=para_118_e_ii&doctype=Standard
-URIDate 2023-03-23

+ Details

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

- Definition

The decrease in intangible assets other than goodwill resulting from classification as held for sale or inclusion in a disposal group classified as held for sale. [Refer: Disposal groups classified as held for sale [member]; Intangible assets other than goodwill]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 38
-IssueDate 2023-01-01
-Paragraph 118
-Subparagraph e
-Clause ii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=38&code=ifrs-tx-2023-en-r&anchor=para_118_e_ii&doctype=Standard
-URIDate 2023-03-23

+ Details

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

- Definition

The amount of assets representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognised. [Refer: Business combinations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2023-01-01
-Paragraph 134
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=36&code=ifrs-tx-2023-en-r&anchor=para_134_a&doctype=Standard
-URIDate 2023-03-23

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2023-01-01
-Paragraph 135
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=36&code=ifrs-tx-2023-en-r&anchor=para_135_a&doctype=Standard
-URIDate 2023-03-23

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2023-01-01
-Paragraph B67
-Subparagraph d
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2023-en-r&anchor=para_B67_d&doctype=Appendix&subtype=B
-URIDate 2023-03-23

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 54
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_54_c&doctype=Standard
-URIDate 2023-03-23

+ Details

Name:	ifrs-full_Goodwill
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of intangible assets and goodwill held by the entity. [Refer: Goodwill; Intangible assets other than goodwill]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 55
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_55&doctype=Standard
-URIDate 2023-03-23

+ Details

Name:	ifrs-full_IntangibleAssetsAndGoodwill
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of identifiable non-monetary assets without physical substance. This amount does not include goodwill. [Refer: Goodwill]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 38
-IssueDate 2023-01-01
-Paragraph 118
-Subparagraph e
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=38&code=ifrs-tx-2023-en-r&anchor=para_118_e&doctype=Standard
-URIDate 2023-03-23

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 54
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_54_c&doctype=Standard
-URIDate 2023-03-23

+ Details

Name:	ifrs-full_IntangibleAssetsOtherThanGoodwill
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Definition

The amount of additions to intangible assets and goodwill.

+ References

No definition available.

+ Details

Name:	su_AggregateAdditionsIntangibleAssetsAndGoodwill
Namespace Prefix:	su_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	ifrs-full_SegmentsAxis=su_OilSandsSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SegmentsAxis=su_RefiningAndMarketingSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: