Summary of Significant Accounting Policies - Contract Balances from Contracts with Customers - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Feb. 28, 2023	Dec. 31, 2022	Feb. 28, 2022	Dec. 31, 2021
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract with customer liability	$ 47,499	$ 70,111		$ 50,211		$ 92,068
Revenue from contract with customer	49,869	38,078
Revenue recognized, previously deferred	2,712	25,760
Current portion of deferred revenue	13,444			$ 13,856
License and milestone fees
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customer	15,031	30,892
Future Technological Improvements
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue recognized, previously deferred		100
Hangzhou Zhongmei Huadong Pharmaceutical Co., Ltd | License and milestone fees
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
License agreement upfront payment receivable						45,000
Revenue recognized, previously deferred		21,600
Current portion of deferred revenue						$ 28,500
Lilly
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
License agreement upfront payment receivable					$ 13,000
Lilly | License and milestone fees
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customer		9,200
Lilly | Upfront payment
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract with customer liability		13,000
KADCYLA | Royalty revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net proceeds from sale of residual rights to receive royalty payments	2,700
Revenue recognized, previously deferred		$ 4,100
Vertex | License and milestone fees
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customer	15,000
Vertex | Upfront payment
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
License agreement upfront payment receivable			$ 15,000
Revenue from contract with customer	$ 15,000