Other financial information - Related-party transactions (Details) - EUR (€)		6 Months Ended
May 25, 2023	Jun. 30, 2023
Other financial information
Percentage of severance payment subject to performance condition	200.00%
Severance payment		€ 0

Percentage of discount to percentage of severance payment subject to performance condition.

No definition available.

Name:	iva_PercentageOfSeverancePaymentSubjectToPerformanceCondition
Namespace Prefix:	iva_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration