License Revenue and Reimbursable Expenses (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		6 Months Ended
	Mar. 31, 2021	Jul. 31, 2017	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
License agreements, upfront payment received		$ 10,000
License agreements, first commercial sale anniversary		10 years
License revenue			$ 51,797	$ 50,113	$ 108,057	$ 98,037
Reimbursable expenses			18,500	0	32,800	0
Receivable of reimbursable development expenses			37,500		37,500
License revenue
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
License revenue			$ 0	$ 0	11,000	$ 0
Collaborative Arrangement | Teijin Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
License agreements, upfront payment received		$ 10,000
Additional payments to be made upon achievement of certain milestones	$ 10,000	$ 40,000
Collaborative Arrangement | Teijin Agreement | License revenue
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
License revenue					10,000
Menarini Group
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Reimbursement of cost					114,600
Upfront payment received					30,000
License					27,400
Inventory					2,600
Menarini Group | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Development and regulatory milestone payments receivable					20,000
Sales milestone payments receivable					$ 300,000