Accounting Principles - Share based payments (Details)	12 Months Ended
Dec. 31, 2020
Accounting Principles
Number of BSA share warrant plan set up	2

Represents the number of BSA share warrant plan set up.

No definition available.

Name:	iva_NumberOfBsaShareWarrantPlanSetUp
Namespace Prefix:	iva_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration