Significant Accounting Polices - Additional Information (Details) - USD ($)			3 Months Ended
	Mar. 19, 2021	Jan. 25, 2021	Mar. 31, 2021	Mar. 31, 2020	Apr. 30, 2021	Dec. 31, 2020
Schedule Of Significant Accounting Policies [Line Items]
Upfront nonrefundable payment		$ 1,000,000
Loan in principal amount		$ 4,000,000
Issuance and bore interest rate		6.00%
Reimbursement payment	$ 14,000,000
Collaboration agreement amount	25,000,000
Development payments	10,000,000
Deferred collaboration funding			$ 20,715,764
Accounts receivable			$ 10,000,000
Accounting Standards Update [Extensible List]			acer:AccountingStandardsUpdate202006Member
Change in accounting principle, accounting standards update, adopted			true
Change in accounting principle, accounting standards update, adoption date			Mar. 31, 2021
Change in accounting principle, accounting standards update, immaterial effect			true
Income tax expense (benefit)			$ 0	$ 0
Cash and Cash Equivalents
Schedule Of Significant Accounting Policies [Line Items]
Investments in money market funds			15,400,000			$ 5,300,000
First Development Payment
Schedule Of Significant Accounting Policies [Line Items]
Collaboration agreement amount			10,000,000
First Development Payment | Subsequent Event
Schedule Of Significant Accounting Policies [Line Items]
Collaboration agreement amount					$ 5,000,000
Performance Obligations
Schedule Of Significant Accounting Policies [Line Items]
Deferred collaboration funding			20,700,000
Cash received			15,000,000
Accounts receivable			10,000,000
Revenue recognized			4,000,000
Offset to research and development expense			300,000
Relief
Schedule Of Significant Accounting Policies [Line Items]
Non-cash reduction recognized in secured loan			4,000,000
Collaboration Agreement | Relief
Schedule Of Significant Accounting Policies [Line Items]
Cash payment received	10,000,000	$ 10,000,000
Reimbursement payment	14,000,000	14,000,000
Repayment of outstanding balance of prior loan and interest	4,000,000	4,000,000
Development and commercial launch costs	20,000,000
Development payments subject new drug application		$ 10,000,000	$ 10,000,000
Development payments subject to new drug application, Installment amount	$ 5,000,000
Net profit split ratio based on territory	60.00%	60.00%
Percentage of royalty revenue received	15.00%	15.00%
Milestone payment to be received	$ 6,000,000	$ 6,000,000
Percentage of development and commercialization services	60.00%
Percentage of payment net profit territory	60.00%
Upfront non-refundable payment received		$ 1,000,000
Collaboration Agreement | Relief | First Development Payment
Schedule Of Significant Accounting Policies [Line Items]
Development payments subject new drug application	$ 10,000,000
Collaboration Agreement | Relief | Second Development Payment
Schedule Of Significant Accounting Policies [Line Items]
Development payments subject new drug application	10,000,000
Collaboration And License Agreement
Schedule Of Significant Accounting Policies [Line Items]
Upfront non-refundable payment received	$ 1,000,000