Research and Collaboration Agreements - Contract Liabilities - Additional Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 161,650	$ 194,922
AbbVie Ireland Unlimited Company | CD71 Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 9,500	$ 16,100
Deferred Revenue Recognition Maturity Year	2023
AbbVie Ireland Unlimited Company | Second Target under Discovery Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 4,000
Deferred Revenue Recognition Maturity Year	2024
Amgen | EGFR Products
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 19,600
Deferred Revenue Recognition Maturity Year	2024
Amgen | Amgen Other Products
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 1,000
Deferred Revenue Recognition Maturity Year	2023
Bristol Myers Squibb Company
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 83,900
Deferred Revenue Recognition Maturity Year	2025
Astellas Pharma Inc.
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 43,700
Deferred Revenue Recognition Maturity Year	2025