XML 107 R93.htm IDEA: XBRL DOCUMENT v3.25.2

Segment Information (Details)	12 Months Ended
	Jun. 30, 2025
Segment Information [Abstract]
Reportable segment	1

X

- Definition

Number of reportable segments.

+ References

No definition available.

+ Details

Name:	athe_NumberOfReportableSegment
Namespace Prefix:	athe_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	ifrs-full_DisclosureOfOperatingSegmentsAbstract
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration