License Revenue and Reimbursable Expenses (Details) - USD ($)	1 Months Ended		3 Months Ended
	Mar. 31, 2021	Jul. 31, 2017	Mar. 31, 2021	Mar. 31, 2020
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
License agreements, upfront payment received		$ 10,000,000.0
License agreements, first commercial sale anniversary		10 years
License revenue			$ 56,261,000	$ 47,923,000
Reimbursable expenses			14,300,000	0
Receivable of reimbursable development expenses	$ 19,000,000.0		19,000,000.0
License revenue
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
License revenue			11,000,000	$ 0
Collaborative Arrangement | Teijin Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
License agreements, upfront payment received		$ 10,000,000.0
Additional payments to be made upon achievement of certain milestones	$ 10,000,000.0	$ 40,000,000.0
Collaborative Arrangement | Teijin Agreement | License revenue
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
License revenue			10,000,000.0
Menarini Group
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Reimbursement of cost			114,600,000
Upfront payment received			30,000,000.0
License			27,400,000
Inventory			2,600,000
Menarini Group | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Development and regulatory milestone payments receivable			20,000,000.0
Sales milestone payments receivable			$ 300,000,000.0