Revenue - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Feb. 29, 2020	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Current contract liability	$ 7,511	$ 8,370
Noncurrent contract liability	0	569
Licensing agreements | EuroFarma
Disaggregation of Revenue [Line Items]
Deferred revenue, upfront payment				$ 2,500
Deferred revenue, enrollment milestone	1,250		$ 1,000
Current contract liability	1,000	800
Noncurrent contract liability	0	$ 600
Revenue entitled to receive upon achieving patient enrollment targets	1,500
Revenue entitled to receive upon achieving additional development milestones	1,000
Revenue entitled to receive upon achieving commercial milestones	2,400
Revenue entitled to receive upon achieving cumulative net sales targets	18,000
Cumulative net sales target threshold	100,000
Incremental cumulative net sales target threshold	$ 100,000