Significant Accounting Policies - Additional Information (Details)	1 Months Ended		3 Months Ended		6 Months Ended	12 Months Ended
	Aug. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2021 USD ($) Segment	Dec. 31, 2019 USD ($)	Jan. 31, 2019 USD ($)
Basis Of Presentation And Significant Accounting Policies [Line Items]
Number of operating segments | Segment					1
Operating lease right-of-use asset		$ 936,000	$ 1,547,000		$ 1,547,000
Operating lease liabilities			$ 2,044,000		$ 2,044,000
ASU 2016-02
Basis Of Presentation And Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted			true		true
Change in accounting principle, accounting standards update, adoption date			Jan. 01, 2020		Jan. 01, 2020
ASU 2018-07
Basis Of Presentation And Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted			true		true
Change in accounting principle, accounting standards update, adoption date			Jan. 01, 2020		Jan. 01, 2020
National Institutes of Health Grant
Basis Of Presentation And Significant Accounting Policies [Line Items]
Grants received			$ 2,900,000		$ 2,900,000
Subsequent Event | National Institutes of Health Grant
Basis Of Presentation And Significant Accounting Policies [Line Items]
Grants received	$ 2,600,000
Alzheimers Association
Basis Of Presentation And Significant Accounting Policies [Line Items]
Research grant awarded							$ 1,000,000.0
Grants received				$ 224,000		$ 776,000
National Institute on Aging of the National Institutes of Health
Basis Of Presentation And Significant Accounting Policies [Line Items]
Research grant awarded		15,200,000
Grants received		7,800,000
Remaining grant to be received		$ 7,400,000