Revenue - Collaboration Agreement - The Astellas Collaboration Agreement (Details)	6 Months Ended
	Jun. 30, 2022 USD ($) item
Revenue
Aggregate amount of the transaction price that is allocated to performance obligations that are unsatisfied or partially satisfied under the agreements	$ 348,414,000
Astellas Collaboration Agreement
Revenue
Number Of Co Development Target | item	3
Number of independent targets | item	2
Aggregate amount of the transaction price that is allocated to performance obligations that are unsatisfied or partially satisfied under the agreements	$ 55,881,000
Astellas Collaboration Agreement | Rights granted, first and second independent target
Revenue
Aggregate amount of the transaction price that is allocated to performance obligations that are unsatisfied or partially satisfied under the agreements	13,502,000
Astellas Collaboration Agreement | Research services and rights granted under the co-exclusive license, first co-development target
Revenue
Aggregate amount of the transaction price that is allocated to performance obligations that are unsatisfied or partially satisfied under the agreements	8,159,000
Astellas Collaboration Agreement | Research services and rights under the co-exclusive license, second co-development target
Revenue
Aggregate amount of the transaction price that is allocated to performance obligations that are unsatisfied or partially satisfied under the agreements	14,200,000
Astellas Collaboration Agreement | Research services and rights under the co-exclusive license, third co-development target
Revenue
Aggregate amount of the transaction price that is allocated to performance obligations that are unsatisfied or partially satisfied under the agreements	$ 6,518,000