Potential proceeds from development payments subject to new drug application.

No definition available.

Name:	acer_PotentialProceedsFromDevelopmentPaymentsSubjectToNewDrugApplication
Namespace Prefix:	acer_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Potential proceeds from second tranche of development payments subject to new drug application.

+ References

No definition available.

+ Details

Name:	acer_PotentialProceedsFromSecondTrancheOfDevelopmentPaymentsSubjectToNewDrugApplication
Namespace Prefix:	acer_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Proceeds from first tranche of development payments subject to new drug application.

+ References

No definition available.

+ Details

Name:	acer_ProceedsFromFirstTrancheOfDevelopmentPaymentsSubjectToNewDrugApplication
Namespace Prefix:	acer_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Second tranche of development payment, expiry date.

+ References

No definition available.

+ Details

Name:	acer_SecondTrancheOfDevelopmentPaymentExpiryDate
Namespace Prefix:	acer_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Written notice period for second tranche of development payment.

+ References

No definition available.

+ Details

Name:	acer_WrittenNoticePeriodForSecondTrancheOfDevelopmentPayment
Namespace Prefix:	acer_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

Name:	us-gaap_SubsequentEventLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=acer_CollaborationAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=acer_ReliefTherapeuticsHoldingAGMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=acer_SecondDevelopmentPaymentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=acer_WaiverAndAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Subsequent Events - Additional Information (Details) - Subsequent Event - Relief - Second Development Payment - USD ($) $ in Millions	Oct. 12, 2021	Oct. 06, 2021	Oct. 04, 2021
Collaboration Agreement
Subsequent Event [Line Items]
Potential proceeds from development payments subject to new drug application			$ 10.0
Proceeds from first tranche of development payments subject to new drug application	$ 5.0
Waiver and Agreement
Subsequent Event [Line Items]
Potential proceeds from second tranche of development payments subject to new drug application		$ 5.0
Second tranche of development payment, expiry date		Jan. 14, 2022
Written notice period (in business days) for second tranche of development payment		15 days