The present value, without deducting any plan assets, of expected future payments required to settle the obligation resulting from employee service in the current and prior periods. [Refer: Plan assets, at fair value]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2024-01-01
-Paragraph 57
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_57_a&doctype=Standard
-URIDate 2024-03-27

+ Details

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

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

- Definition

The amount of benefit obligation percentage.

+ References

No definition available.

+ Details

Name:	iva_BenefitObligationPercentage
Namespace Prefix:	iva_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of increase (decrease) in a defined benefit obligation that would have been caused by an increase in a significant actuarial assumption that was reasonably possible at the end of the reporting period.

+ References

No definition available.

+ Details

Name:	iva_IncreaseDecreaseInDefinedBenefitObligationDueToReasonablyPossibleIncreaseInActuarialAssumptionPercent
Namespace Prefix:	iva_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of reasonably possible increase or decrease in actuarial assumption

+ References

No definition available.

+ Details

Name:	iva_PercentageOfReasonablyPossibleIncreaseOrDecreaseInActuarialAssumption
Namespace Prefix:	iva_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	ifrs-full_ActuarialAssumptionsAxis=ifrs-full_ActuarialAssumptionOfDiscountRatesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ActuarialAssumptionsAxis=iva_ActuarialAssumptionOfDiscountRatesAt3.15PercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ActuarialAssumptionsAxis=iva_ActuarialAssumptionOfDiscountRatesAt3.40PercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ActuarialAssumptionsAxis=iva_ActuarialAssumptionOfDiscountRatesAt3.65PercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ActuarialAssumptionsAxis=iva_ActuarialAssumptionOfDiscountRatesAt2.95PercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ActuarialAssumptionsAxis=iva_ActuarialAssumptionOfDiscountRatesAt3.20PercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ActuarialAssumptionsAxis=iva_ActuarialAssumptionOfDiscountRatesAt3.45PercentOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ActuarialAssumptionsAxis=iva_ActuarialAssumptionOfDiscountRatesAt3.45PercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ActuarialAssumptionsAxis=iva_ActuarialAssumptionOfDiscountRatesAt3.70PercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ActuarialAssumptionsAxis=iva_ActuarialAssumptionOfDiscountRatesAt3.95PercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Provisions for retirement benefit obligations - Sensitivity analysis (Details) - EUR (€) € in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Provisions for retirement benefit obligations
Benefit obligation at December 31	€ 1,762	€ 1,559	€ 1,234
Discount rate
Provisions for retirement benefit obligations
Percentage of reasonably possible increase or decrease in actuarial assumption	0.25%
Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption (as a percent)	2.10%	2.20%	2.30%
Discount rate at 3.15%
Provisions for retirement benefit obligations
Benefit Obligation Percentage	3.15%
Benefit obligation at December 31	€ 1,799
Discount rate at 3.40%
Provisions for retirement benefit obligations
Benefit Obligation Percentage	3.40%
Benefit obligation at December 31	€ 1,762
Discount rate at 3.65%
Provisions for retirement benefit obligations
Benefit Obligation Percentage	3.65%
Benefit obligation at December 31	€ 1,726
Discount rate at 2.95%
Provisions for retirement benefit obligations
Benefit Obligation Percentage		2.95%
Benefit obligation at December 31		€ 1,595
Discount rate at 3.20%
Provisions for retirement benefit obligations
Benefit Obligation Percentage		3.20%
Benefit obligation at December 31		€ 1,559
Discount rate at 3.45%
Provisions for retirement benefit obligations
Benefit Obligation Percentage		3.45%	3.45%
Benefit obligation at December 31		€ 1,525
Discount rate at 3.45%
Provisions for retirement benefit obligations
Benefit obligation at December 31			€ 1,263
Discount rate at 3.70%
Provisions for retirement benefit obligations
Benefit Obligation Percentage			3.70%
Benefit obligation at December 31			€ 1,234
Discount rate at 3.95%
Provisions for retirement benefit obligations
Benefit Obligation Percentage			3.95%
Benefit obligation at December 31			€ 1,205