The spot exchange rate at the end of the reporting period. Exchange rate is the ratio of exchange for two currencies. Spot exchange rate is the exchange rate for immediate delivery.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
-Paragraph 112
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_ClosingForeignExchangeRate
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of revenue from contracts with customers. A customer is a party that has contracted with an entity to obtain goods or services that are an output of the entity’s ordinary activities in exchange for consideration.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 15
-IssueDate 2024-01-01
-Paragraph 114
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2024-en-r&anchor=para_114&doctype=Standard
-URIDate 2024-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 15
-IssueDate 2024-01-01
-Paragraph 113
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2024-en-r&anchor=para_113_a&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_RevenueFromContractsWithCustomers
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This amount represents the information of invoiced to counterparty.

+ References

No definition available.

+ Details

Name:	iva_AmountInvoicedToCounterparty
Namespace Prefix:	iva_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This amount represents the information of invoiced to counterparty for additional payment.

+ References

No definition available.

+ Details

Name:	iva_AmountInvoicedToCounterpartyForAdditionalPayment
Namespace Prefix:	iva_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This amount represents the information of invoiced to counterparty for initial payment.

+ References

No definition available.

+ Details

Name:	iva_AmountInvoicedToCounterpartyForInitialPayment
Namespace Prefix:	iva_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of tax credit research from current year, classified as current.

+ References

No definition available.

+ Details

Name:	iva_CurrentTaxCreditResearchCurrentYear
Namespace Prefix:	iva_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Disclosure of information about collaborative arrangement and arrangement other than collaborative applicable to revenue-generating activity or operations.

+ References

No definition available.

+ Details

Name:	iva_IfrsCollaborativeArrangementAndArrangementOtherThanCollaborativeLineItems
Namespace Prefix:	iva_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

License agreement, payables for credit notes issued.

+ References

No definition available.

+ Details

Name:	iva_LicenseAgreementPayablesForCreditNotesIssued
Namespace Prefix:	iva_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Value of credit note recognized during the period under license and collaborative arrangement.

+ References

No definition available.

+ Details

Name:	iva_LicenseAndCollaborationArrangementCreditNoteRecognized
Namespace Prefix:	iva_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount received by the entity from licensing and collaborative arrangements, attributable to withholding taxes.

+ References

No definition available.

+ Details

Name:	iva_LicensingAndCollaborationAgreementAmountReceivedAttributableToWithholdingTaxes
Namespace Prefix:	iva_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount paid on licensing arrangements.

+ References

No definition available.

+ Details

Name:	iva_ProceedsFromLicensingArrangements
Namespace Prefix:	iva_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount paid on licensing arrangements after deduction of withholding taxes

+ References

No definition available.

+ Details

Name:	iva_ProceedsFromLicensingArrangementsAfterDeductionOfWithholdingTaxes
Namespace Prefix:	iva_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	iva_IfrsCollaborativeArrangementAndArrangementOtherThanCollaborativeAxis=iva_LicensingAndCollaborationAgreementWithCttqMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

Notes to the interim condensed consolidated statement of (income) loss - Revenues and other income - Additional information (Details) € in Thousands, $ in Millions					1 Months Ended		6 Months Ended
	Jul. 07, 2025 EUR (€) $ / €	Jul. 07, 2025 USD ($) $ / €	May 09, 2025 EUR (€) $ / €	May 09, 2025 USD ($) $ / €	May 31, 2025 EUR (€)	May 31, 2025 USD ($)	Jun. 30, 2025 EUR (€) $ / €	Jun. 30, 2024 EUR (€) $ / €	Jun. 30, 2025 USD ($) $ / €	May 07, 2025 $ / €	Dec. 31, 2024 $ / €
Ifrs Collaborative Arrangement And Arrangement Other Than Collaborative [Line items]
Revenue							€ 4,454	€ 41
Tax credits of current year							€ 1,100
Exchange rate \| $ / €							1.172	1.0705	1.172		1.0389
Licensing and collaboration agreement with CTTQ
Ifrs Collaborative Arrangement And Arrangement Other Than Collaborative [Line items]
Revenue							€ 4,400
Amount invoiced to counterparty			€ 9,400	$ 10.5
Amount invoiced to counterparty for milestone payment			8,900	10.0
Amount invoiced to counterparty for additional payment			€ 500	$ 0.5
License agreement, payables for credit notes issued							€ 4,300		$ 5.0
Exchange rate \| $ / €			1.125	1.125			1.125		1.125	1.172
License and collaboration arrangement, credit note recognized			€ 4,400		€ 4,400	$ 5.0	€ 4,300
Licensing and collaboration agreement with CTTQ \| Receipt of payments under Licensing arrangements
Ifrs Collaborative Arrangement And Arrangement Other Than Collaborative [Line items]
Amount received on licensing arrangements	€ 8,500	$ 9.5
Amount received attributable to withholding taxes	€ 900	$ 1.1
Exchange rate \| $ / €	1.173	1.173					1.172		1.172
Amount received on licensing arrangements after deduction of withholding taxes	€ 8,100