3.24.2.u1 html 88 192 1 false 31 0 false 5 false false R1.htm 100000 - Document - Document And Entity Information Sheet http://www.acastipharma.com/20240630/taxonomy/role/statement-document-and-entity-information Document And Entity Information Cover 1 false false R2.htm 100010 - Statement - Condensed Consolidated Interim Balance Sheet (Unaudited) Sheet http://www.acastipharma.com/20240630/taxonomy/role/StatementCondensedConsolidatedInterimBalanceSheetUnaudited Condensed Consolidated Interim Balance Sheet (Unaudited) Statements 2 false false R3.htm 100030 - Statement - Condensed Consolidated Interim Balance Sheet (Unaudited) (Parenthetical) Sheet http://www.acastipharma.com/20240630/taxonomy/role/StatementCondensedConsolidatedInterimBalanceSheetUnauditedParenthetical Condensed Consolidated Interim Balance Sheet (Unaudited) (Parenthetical) Statements 3 false false R4.htm 100040 - Statement - Condensed Consolidated Interim Statements of Loss and Comprehensive Loss (Unaudited) Sheet http://www.acastipharma.com/20240630/taxonomy/role/StatementCondensedConsolidatedInterimStatementsOfLossAndComprehensiveLossUnaudited Condensed Consolidated Interim Statements of Loss and Comprehensive Loss (Unaudited) Statements 4 false false R5.htm 100050 - Statement - Condensed Consolidated Statements of Changes in Shareholder's Equity (Unaudited) Sheet http://www.acastipharma.com/20240630/taxonomy/role/StatementCondensedConsolidatedStatementsOfChangesInShareholdersEquityUnaudited Condensed Consolidated Statements of Changes in Shareholder's Equity (Unaudited) Statements 5 false false R6.htm 100060 - Statement - Condensed Consolidated Interim Statements of Cash Flows (Unaudited) Sheet http://www.acastipharma.com/20240630/taxonomy/role/statement-condensed-consolidated-interim-statements-of-cash-flows-unaudited Condensed Consolidated Interim Statements of Cash Flows (Unaudited) Statements 6 false false R7.htm 995410 - Disclosure - Pay vs Performance Disclosure Sheet http://xbrl.sec.gov/ecd/role/PvpDisclosure Pay vs Performance Disclosure Notes 7 false false R8.htm 995445 - Disclosure - Insider Trading Arrangements Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements Insider Trading Arrangements Notes 8 false false R9.htm 995455 - Disclosure - Note 1 - Nature of Operation Sheet http://www.acastipharma.com/20240630/taxonomy/role/statement-note-1-nature-of-operation Note 1 - Nature of Operation Notes 9 false false R10.htm 995465 - Disclosure - Note 2 - Summary of Significant Accounting Policies Sheet http://www.acastipharma.com/20240630/taxonomy/role/statement-note-2-summary-of-significant-accounting-policies Note 2 - Summary of Significant Accounting Policies Notes 10 false false R11.htm 995475 - Disclosure - Note 3 - Fair Value Measurements Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote3FairValueMeasurements1 Note 3 - Fair Value Measurements Notes 11 false false R12.htm 995485 - Disclosure - Note 4 - Receivables Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote4Receivables Note 4 - Receivables Notes 12 false false R13.htm 995495 - Disclosure - Note 5 - Short-term Investments Sheet http://www.acastipharma.com/20240630/taxonomy/role/statement-note-5-shortterm-investments- Note 5 - Short-term Investments Notes 13 false false R14.htm 995505 - Disclosure - Note 6 - Trade and other payables Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote6TradeAndOtherPayables Note 6 - Trade and other payables Notes 14 false false R15.htm 995515 - Disclosure - Note 7 - Leases Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote7Leases Note 7 - Leases Notes 15 false false R16.htm 995525 - Disclosure - Note 8 - Shareholders' Equity Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote8ShareholdersEquity Note 8 - Shareholders' Equity Notes 16 false false R17.htm 995535 - Disclosure - Note 9 - Stock Based Compensation Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote9StockBasedCompensation Note 9 - Stock Based Compensation Notes 17 false false R18.htm 995545 - Disclosure - Note 10 - Loss per share Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote10LossPerShare Note 10 - Loss per share Notes 18 false false R19.htm 995555 - Disclosure - Note 11 - Commitments and Contingencies Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote11CommitmentsAndContingencies Note 11 - Commitments and Contingencies Notes 19 false false R20.htm 995565 - Disclosure - Note 12 - Restructuring Costs Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote12RestructuringCosts Note 12 - Restructuring Costs Notes 20 false false R21.htm 995575 - Disclosure - Note 2 - Significant Accounting Policies (Policies) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote2SignificantAccountingPoliciesPolicies Note 2 - Significant Accounting Policies (Policies) Policies http://www.acastipharma.com/20240630/taxonomy/role/statement-note-2-summary-of-significant-accounting-policies 21 false false R22.htm 995585 - Disclosure - Note 3 - Fair Value Measurements (Tables) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote3FairValueMeasurementsTables Note 3 - Fair Value Measurements (Tables) Tables http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote3FairValueMeasurements1 22 false false R23.htm 995595 - Disclosure - Note 4 - Receivables (Tables) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote4ReceivablesTables Note 4 - Receivables (Tables) Tables http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote4Receivables 23 false false R24.htm 995605 - Disclosure - Note 5 - Short-term Investments (Tables) Sheet http://www.acastipharma.com/20240630/taxonomy/role/statement-note-5-shortterm-investments-tables Note 5 - Short-term Investments (Tables) Tables http://www.acastipharma.com/20240630/taxonomy/role/statement-note-5-shortterm-investments- 24 false false R25.htm 995615 - Disclosure - Note 6 - Trade and other payables (Tables) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote6TradeAndOtherPayablesTables Note 6 - Trade and other payables (Tables) Tables http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote6TradeAndOtherPayables 25 false false R26.htm 995625 - Disclosure - Note 7 - Leases (Tables) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote7LeasesTables Note 7 - Leases (Tables) Tables http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote7Leases 26 false false R27.htm 995635 - Disclosure - Note 8 - Shareholders' Equity (Tables) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote8ShareholdersEquityTables Note 8 - Shareholders' Equity (Tables) Tables http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote8ShareholdersEquity 27 false false R28.htm 995645 - Disclosure - Note 9 - Stock Based Compensation (Tables) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote9StockBasedCompensationTables Note 9 - Stock Based Compensation (Tables) Tables http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote9StockBasedCompensation 28 false false R29.htm 995655 - Disclosure - Note 10 - Loss per share (Tables) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote10LossPerShareTables Note 10 - Loss per share (Tables) Tables http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote10LossPerShare 29 false false R30.htm 995665 - Disclosure - Note 1 - Nature of Operation (Additional Information) (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote1NatureOfOperationAdditionalInformationDetails Note 1 - Nature of Operation (Additional Information) (Details) Details http://www.acastipharma.com/20240630/taxonomy/role/statement-note-1-nature-of-operation 30 false false R31.htm 995675 - Disclosure - Note 3 - Fair Value Measurements (Additional Information) (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote3FairValueMeasurementsAdditionalInformationDetails Note 3 - Fair Value Measurements (Additional Information) (Details) Details http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote3FairValueMeasurementsTables 31 false false R32.htm 995685 - Disclosure - Note 3 - Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote3FairValueMeasurementsScheduleOfAssetsAndLiabilitiesMeasuredAtFairValueDetails Note 3 - Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value (Details) Details 32 false false R33.htm 995695 - Disclosure - Note 4 - Receivables - Receivables (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote4ReceivablesReceivablesDetails Note 4 - Receivables - Receivables (Details) Details 33 false false R34.htm 995715 - Disclosure - Note 5 - Short-term Investments - Marketable Securities (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/statement-note-5-shortterm-investments-marketable-securities-details Note 5 - Short-term Investments - Marketable Securities (Details) Details 34 false false R35.htm 995725 - Disclosure - Note 5 - Short-term Investments - Marketable Securities (Details) (Parentheticals) Sheet http://www.acastipharma.com/20240630/taxonomy/role/statement-note-5-shortterm-investments-marketable-securities-details-parentheticals Note 5 - Short-term Investments - Marketable Securities (Details) (Parentheticals) Details 35 false false R36.htm 995735 - Disclosure - Note 6 - Trade and other payables - Trade and other payables (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote6TradeAndOtherPayablesTradeAndOtherPayablesDetails Note 6 - Trade and other payables - Trade and other payables (Details) Details 36 false false R37.htm 995755 - Disclosure - Note 7 - Leases - Supplemental lease expense (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote7LeasesSupplementalLeaseExpenseDetails Note 7 - Leases - Supplemental lease expense (Details) Details 37 false false R38.htm 995765 - Disclosure - Note 7 -Leases - Schedule of Lease Costs Recognized for Operating Leases (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote7LeasesScheduleOfLeaseCostsRecognizedForOperatingLeasesDetails Note 7 -Leases - Schedule of Lease Costs Recognized for Operating Leases (Details) Details 38 false false R39.htm 995785 - Disclosure - Note 7 - Leases (Additional Information) (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote7LeasesAdditionalInformationDetails Note 7 - Leases (Additional Information) (Details) Details http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote7LeasesTables 39 false false R40.htm 995795 - Disclosure - Note 8 - Shareholders' Equity - Schedule Of Derivative Liabilities At Fair Value (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote8ShareholdersEquityScheduleOfDerivativeLiabilitiesAtFairValueDetails Note 8 - Shareholders' Equity - Schedule Of Derivative Liabilities At Fair Value (Details) Details 40 false false R41.htm 995805 - Disclosure - Note 8 - Shareholders' Equity - Fair Value Measurement Inputs and Valuation Techniques (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote8ShareholdersEquityFairValueMeasurementInputsAndValuationTechniquesDetails Note 8 - Shareholders' Equity - Fair Value Measurement Inputs and Valuation Techniques (Details) Details 41 false false R42.htm 995815 - Disclosure - Note 8 - Shareholders' Equity (Details Textual) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote8ShareholdersEquityDetailsTextual Note 8 - Shareholders' Equity (Details Textual) Details http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote8ShareholdersEquityTables 42 false false R43.htm 995825 - Disclosure - Note 9 - Stock Based Compensation (Details Textual) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote9StockBasedCompensationDetailsTextual Note 9 - Stock Based Compensation (Details Textual) Details http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote9StockBasedCompensationTables 43 false false R44.htm 995835 - Disclosure - Note 9 - Stock Based Compensation - Activities Within the Stock Option Plan (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote9StockBasedCompensationActivitiesWithinTheStockOptionPlanDetails Note 9 - Stock Based Compensation - Activities Within the Stock Option Plan (Details) Details 44 false false R45.htm 995845 - Disclosure - Note 9 - Stock-based Compensation - Schedule of weighted average grant date fair value of awards for options granted (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote9StockbasedCompensationScheduleOfWeightedAverageGrantDateFairValueOfAwardsForOptionsGrantedDetails Note 9 - Stock-based Compensation - Schedule of weighted average grant date fair value of awards for options granted (Details) Details 45 false false R46.htm 995855 - Disclosure - Note 9 - Stock Based Compensation - Compensation Expense (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote9StockBasedCompensationCompensationExpenseDetails Note 9 - Stock Based Compensation - Compensation Expense (Details) Details 46 false false R47.htm 995865 - Disclosure - Note 10 - Loss per share - Schedule of diluted net loss per share attributable to common shareholders (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote10LossPerShareScheduleOfDilutedNetLossPerShareAttributableToCommonShareholdersDetails Note 10 - Loss per share - Schedule of diluted net loss per share attributable to common shareholders (Details) Details 47 false false R48.htm 995875 - Disclosure - Note 11 - Commitments and Contingencies (Additional Information) (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote11CommitmentsAndContingenciesAdditionalInformationDetails Note 11 - Commitments and Contingencies (Additional Information) (Details) Details http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote11CommitmentsAndContingencies 48 false false R49.htm 995885 - Disclosure - Note 12 - Restructuring Costs (Additional Information) (Details) Sheet http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote12RestructuringCostsAdditionalInformationDetails Note 12 - Restructuring Costs (Additional Information) (Details) Details http://www.acastipharma.com/20240630/taxonomy/role/DisclosureNote12RestructuringCosts 49 false false All Reports Book All Reports acst-20240630.htm acst-20240630.xsd img181343341_0.jpg img181343341_1.jpg img181343341_2.jpg img181343341_3.jpg img181343341_4.jpg img181343341_5.jpg img181343341_6.jpg http://fasb.org/us-gaap/2024 http://xbrl.sec.gov/dei/2024 http://xbrl.sec.gov/ecd/2024 false false