Financial debt - Financial debt (Details) - EUR (€) € in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financial debt
Bank borrowings	€ 45,197	€ 27,206	€ 29,689
Derivatives instruments	97,715	10,265	9,876
Accrued interest payable on loans	4,477	3,719	316
Lease liabilities	4,654	6,565	4,510
Royalty certificates liabilities	29,207	6,327
Total debt	€ 181,250	€ 54,082	€ 44,390	€ 10,119

The amount of financial liabilities classified as derivative instruments. [Refer: Financial assets; Derivatives [member]]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
-Paragraph 55
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_55&doctype=Standard
-URIDate 2024-03-27

+ Details

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

- References

No definition available.

+ Details

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

- Definition

The amount of interest recognised as a liability.

+ References

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

- Definition

The amount of liabilities related to the entity's leases. Lease is a contract, or part of a contract, that conveys the right to use an underlying asset for a period of time in exchange for consideration.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 16
-IssueDate 2024-01-01
-Paragraph 47
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2024-en-r&anchor=para_47_b&doctype=Standard
-URIDate 2024-03-27

+ Details

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

- Definition

The amount of loans received.

+ References

+ Details

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

- Definition

Debt, financial

+ References

No definition available.

+ Details

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

- Definition

The non-current portion of non-current royalty certificates issued.

+ References

No definition available.

+ Details

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