XML 144 R133.htm IDEA: XBRL DOCUMENT v3.19.1

21. Employees benefits (Details 7)	12 Months Ended
	Dec. 31, 2018
Life expectation | Increase of 1 year
SummaryOfEmployeeBenefitsLineItems [Line Items]
Impact on present value of the defined benefit obligations	Increase of R$48,558
Life expectation | Decrease of 1 year
SummaryOfEmployeeBenefitsLineItems [Line Items]
Impact on present value of the defined benefit obligations	Decrease of R$49,705
Funded plan | Discount rate | Increase of 1.0%
SummaryOfEmployeeBenefitsLineItems [Line Items]
Impact on present value of the defined benefit obligations	Decrease of R$263,661
Funded plan | Discount rate | Decrease of 1.0%
SummaryOfEmployeeBenefitsLineItems [Line Items]
Impact on present value of the defined benefit obligations	Increase of R$319,455
Funded plan | Wage increase rate | Increase of 1.0%
SummaryOfEmployeeBenefitsLineItems [Line Items]
Impact on present value of the defined benefit obligations	Increase of R$31,418
Funded plan | Wage increase rate | Decrease of 1.0%
SummaryOfEmployeeBenefitsLineItems [Line Items]
Impact on present value of the defined benefit obligations	Decrease of R$27,019

X

- References

No definition available.

+ Details

Name:	SBS_ImpactOnPresentValueOfDefinedBenefitObligations
Namespace Prefix:	SBS_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	SBS_SummaryOfEmployeeBenefitsLineItems
Namespace Prefix:	SBS_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	SBS_SensitivityAnalysisAxis=SBS_LifeExpectationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	SBS_IncreaseDecreaseAxis=SBS_IncreaseOfYearMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	SBS_IncreaseDecreaseAxis=SBS_DecreaseOfYearMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

Name:	SBS_SensitivityAnalysisAxis=SBS_DiscountRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_RangeAxis=SBS_IncreaseOfOnePercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_RangeAxis=SBS_DecreaseOfOnePercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	SBS_SensitivityAnalysisAxis=SBS_WageIncreaseRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: