Note 9 - Government Assistance - Government Assistance (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Mar. 31, 2021
Receivables [Abstract]
Investment tax credit	$ 353	$ 339

The amount of investment tax credit receivable as of the balance sheet date.

No definition available.

Name:	acst_InvestmentTaxCreditReceivable
Namespace Prefix:	acst_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant