Revenue - Schedule of Collaboration Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation Of Revenue [Line Items]
Revenue	$ 6,554	$ 3,500	$ 27,016	$ 3,500
Neurocrine Biosciences [Member] | Collaboration Revenue [Member]
Disaggregation Of Revenue [Line Items]
Recognition of the transaction price	5,246		23,006
Research and development services	1,308		4,010
Revenue	$ 6,554	3,500	$ 27,016	3,500
Flexion [Member] | Collaboration Revenue [Member]
Disaggregation Of Revenue [Line Items]
Recognition of the transaction price		3,000		3,000
Milestone payment		$ 500		$ 500