Company Information - Reinvestment of short-term USD deposits (Details) $ in Millions	1 Months Ended	2 Months Ended
Nov. 30, 2020 item	Oct. 31, 2020 USD ($)
Company Information
Reinvestment of short-term USD deposits \| $		$ 9
Number of short-term deposits \| item	2

Amount of short-term deposits reinvested during the period.

No definition available.

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