Income (loss) per share - Additional Information (Details) - shares	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income (Loss) Per Share [Abstract]
Number of instruments with potential future dilutive effect not included in calculation of diluted earnings per share (in shares)	3,479,983	5,959,104	5,145,914

The number of instruments (including contingently issuable shares) that could potentially dilute basic earnings per share in the future, but were not included in the calculation of diluted earnings per share because they are antidilutive for the period(s) presented.

No definition available.

Name:	inpha_NumberOfInstrumentsWithPotentialFutureDilutiveEffectNotIncludedInCalculationOfDilutedEarningsPerShare
Namespace Prefix:	inpha_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration