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

The nominal value of capital issued.

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

The nominal value per share.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2017-01-01
-Paragraph 79
-Subparagraph a
-Clause iii
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_79_a_iii&doctype=Standard
-URIDate 2017-03-09

Name:	ifrs-full_ParValuePerShare
Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

The cash inflow from the issuing of ordinary shares. [Refer: Ordinary shares [member]]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 7
-IssueDate 2017-01-01
-Paragraph 17
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2017-03-01&anchor=para_17&doctype=Standard
-URIDate 2017-03-09

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

The decrease in equity resulting from the purchase of treasury shares. [Refer: Treasury shares]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2017-01-01
-Paragraph 106
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_106_d&doctype=Standard
-URIDate 2017-03-09

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

An entity’s own equity instruments, held by the entity or other members of the consolidated group.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 1
-IssueDate 2017-01-01
-Paragraph 78
-Subparagraph e
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_78_e&doctype=Standard
-URIDate 2017-03-09

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 32
-IssueDate 2017-01-01
-Paragraph 34
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=32&date=2017-03-01&anchor=para_34&doctype=Standard
-URIDate 2017-03-09

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

The cash inflow from the issuing of ordinary shares net of fees.

No definition available.

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

Represents the number of common shares purchased for cancellation.

No definition available.

Name:	su_PurchaseOfCommonSharesForCancellationInShares
Namespace Prefix:	su_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

The amount of treasury shares authorized to be purchased.

No definition available.

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

The repurchase of average per share.

No definition available.