XML 75 R61.htm IDEA: XBRL DOCUMENT
v3.25.2

Income Tax - Schedule of Income Tax (Parentheticals) (Details) | 12 Months Ended
--- | ---
Jun. 30, 2025 | Jun. 30, 2024 | Jun. 30, 2023
Schedule of Income Tax [Abstract] |  |  |
Prima facie tax on net loss before income tax | 25.00% | 25.00% | 25.00%

X
- Definition Prima facie tax on net loss before income tax. + References No definition available. + Details
Name: | athe_PrimaFacieTaxOnNetLossBeforeIncomeTax
Namespace Prefix: | athe_
Data Type: | dtr:percentItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | athe_ScheduleOfIncomeTaxAbstract
Namespace Prefix: | athe_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration