Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Other Income and Expenses [Abstract]
Interest expense	$ (5,033)	$ (4,945)	$ (14,593)	$ (14,430)
Interest expense on nonrecourse liability related to sale of future royalties	(892)	(1,143)	(2,896)	(3,228)
Total	(5,925)	(6,088)	(17,489)	(17,658)
Amortization of deferred financing costs and debt discount	$ 4,400	$ 4,200	$ 13,037	$ 12,351