Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue	[1]	$ 27	$ 35,741	$ 92	$ 36,294
Net loss		$ (63,890)	$ (36,323)	$ (130,849)	$ (104,467)
Net loss per common share, basic (in dollars per share)		$ (0.26)	$ (0.15)	$ (0.52)	$ (0.43)
Net loss per common share, diluted (in dollars per share)		$ (0.26)	$ (0.15)	$ (0.52)	$ (0.43)
GSK | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | Adjustment To Revenue Related To Change In Estimate
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue			$ 35,300		$ 35,300
Net loss			$ 35,300		$ 35,300
Net loss per common share, basic (in dollars per share)			$ 0.14		$ 0.14
Net loss per common share, diluted (in dollars per share)			$ 0.14		$ 0.14

[1] (1)    None of the revenue for the three and six months ended June 30, 2023 was from a related-party. Substantially all of the revenue for the three and six months ended June 30, 2022 was from a related-party.