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

The amount of risk exposure associated with financial instruments with a shared characteristic that identifies a concentration of risks. [Refer: Financial instruments, class [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2019-01-01
-Paragraph B8
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_B8_c&doctype=Appendix&subtype=B
-URIDate 2019-03-27

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

The increase (decrease) in equity, before tax, as a result of a decrease in a designated risk exposure that was reasonably possible at the end of the reporting period.

No definition available.

Name:	ssl_IncreaseDecreaseInEquityBeforeTaxDueToReasonablyPossibleDecreaseInDesignatedRiskExposure
Namespace Prefix:	ssl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The increase (decrease) in profit (loss), before tax, as a result of a decrease in a designated risk exposure that was reasonably possible at the end of the reporting period.

No definition available.

Name:	ssl_IncreaseDecreaseInProfitLossBeforeTaxDueToReasonablyPossibleDecreaseInDesignatedRiskExposure
Namespace Prefix:	ssl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The amount of risk exposure associated with financial assets with a shared characteristic that identifies a concentration of risks.

No definition available.

Name:	ssl_RiskExposureAssociatedWithAssetsSharingCharacteristic
Namespace Prefix:	ssl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of risk exposure associated with financial liabilities with a shared characteristic that identifies a concentration of risks.

No definition available.

Name:	ssl_RiskExposureAssociatedWithLiabilitiesSharingCharacteristic
Namespace Prefix:	ssl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The reasonably possible percentage of change in the designated risk exposure used to determine the financial impact in a sensitivity analysis. A decrease would result in a positive change to equity and income. An increase would result in a negative change to equity and income in the same amounts.

No definition available.

Name:	ssl_SensitivityAnalysisPercentageOfReasonablyPossibleChangeInRiskExposure
Namespace Prefix:	ssl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Name:	ifrs-full_TypesOfRisksAxis=ifrs-full_CurrencyRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_CurrencyAxis=currency_EUR
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_CounterpartiesAxis=ssl_ExternalCounterpartiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_CounterpartiesAxis=ssl_CounterpartiesWithinConsolidatedEntityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_CurrencyAxis=currency_USD
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_ClassesOfFinancialLiabilitiesAxis=ssl_LongTermDebtIncludingLeaseLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_ClassesOfFinancialLiabilitiesAxis=ssl_TradeAndOtherPayablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_ClassesOfFinancialAssetsAxis=ssl_LongTermReceivablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_ClassesOfFinancialAssetsAxis=ssl_TradeAndOtherReceivablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: