Note 8 - Share-based Payments (Details Textual) - Warrants [member]	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025
Statement Line Items [Line Items]
Share based compensation, expiration period (Year)	10 years
Percentage of total equity	3.10%	4.30%

Represents the expiration period of a share based compensation award.

No definition available.

Name:	evax_ShareBasedCompensationExpirationPeriod
Namespace Prefix:	evax_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration