Research Collaboration and Exclusive License Agreement - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Research And Development Arrangement Contract To Perform For Others [Line Items]
Deferred revenue current	$ 5,065	$ 5,065	$ 1,950
Accounts receivable outstanding	375	375	8,000
Merck Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Revenue recognized	500	900	$ 0
Deferred revenue	7,900	7,900
Deferred revenue current	$ 5,100	$ 5,100

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

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