License and Other Agreements - Revenue Participation Rights (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Aug. 10, 2020
License and other agreements
Non-cash interest expense on liability related to sale of future royalties		$ 11,570,000	$ 5,155,000	$ 19,995,000	$ 11,972,000
2018 RPI Funding Agreement
License and other agreements
Proceeds from royalty agreement	$ 100,000,000
Non-cash interest expense on liability related to sale of future royalties				$ 19,995,000	$ 11,972,000
2020 RPI Funding Agreement | Subsequent Event
License and other agreements
Sales-based participation rights sold, value						$ 250,000,000
Revenue Participation Right, tranche one | 2018 RPI Funding Agreement
License and other agreements
Participation rate for revenue participation right (percent)	2.10%
Revenue Participation Right, tranche one | 2018 RPI Funding Agreement | Maximum
License and other agreements
Annual global net sales threshold for revenue participation right	$ 1,500,000,000
Revenue Participation Right, tranche two | 2018 RPI Funding Agreement
License and other agreements
Participation rate for revenue participation right (percent)	1.50%