XML 191 R169.htm IDEA: XBRL DOCUMENT v3.22.1

Post-employment Benefits - Additional Information (Detail) - BRL (R$) R$ in Thousands	5 Months Ended	12 Months Ended
	May 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Health Plan
Expected duration of contribution to Social Security (Instituto Nacional do Seguro Social), or "INSS" for entitled to defined benefit plan	20 years
Expected uninterrupted service duration for entitled to defined benefit plan	15 years
Sponsor contribution to defined contribution plans		R$ 217	R$ 214	R$ 215
Weighted average duration of defined benefit obligation		9 years 7 months 6 days
Change in methods for preparing the sensitivity analysis		There was no change in relation to previous years in the methods and assumptions used in preparing the sensitivity analysis.
Defined benefit [member] | CLE [member]
Health Plan
Sponsor contribution to defined contribution plans		R$ 5,166	7,044	R$ 4,349
Defined benefit [member] | CLE [member] | Defined benefit obligation [member]
Health Plan
Sponsor contribution to defined contribution plans		60,560
Health plan [member]
Health Plan
Sponsor contribution to defined contribution plans		R$ 25,169	R$ 26,804
Weighted average duration of defined benefit obligation		11 years 8 months 12 days	14 years 10 months 24 days

X

- Definition

The expected duration of contribution to Social Security (Instituto Nacional do Seguro Social), or "INSS" for entitled to a defined benefit plan for employess.

+ References

No definition available.

+ Details

Name:	csan_ExpectedDurationOfContributionToSocialSecurityForEntitledToDefinedBenefitPlan
Namespace Prefix:	csan_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The expected service duration for entitled to a defined benefit plan for employess.

+ References

No definition available.

+ Details

Name:	csan_ExpectedServiceDurationForEntitledToDefinedBenefitPlan
Namespace Prefix:	csan_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The decrease (increase) in the net defined benefit liability (asset) resulting from contributions to a defined benefit plan. [Refer: Net defined benefit liability (asset); Defined benefit plans [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2021-01-01
-Paragraph 141
-Subparagraph f
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2021-en-r&anchor=para_141_f&doctype=Standard
-URIDate 2021-03-24

+ Details

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

X

- Definition

The description of changes in the methods and assumptions used in preparing a sensitivity analysis for significant actuarial assumptions. [Refer: Actuarial assumptions [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2021-01-01
-Paragraph 145
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2021-en-r&anchor=para_145_c&doctype=Standard
-URIDate 2021-03-24

+ Details

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

X

- Definition

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.

+ References

No definition available.

+ Details

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

X

- Definition

The weighted average duration of a defined benefit obligation. [Refer: Weighted average [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2021-01-01
-Paragraph 147
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2021-en-r&anchor=para_147_c&doctype=Standard
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_WeightedAverageDurationOfDefinedBenefitObligation2019
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	ifrs-full_DefinedBenefitPlansAxis=csan_FuturaPensionPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=csan_CLEMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_NonadjustingEventsAfterReportingPeriodAxis=csan_DefinedBenefitObligationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_DefinedBenefitPlansAxis=csan_ComgasPensionPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: