Revenue (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended				6 Months Ended
	Dec. 31, 2020	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2020	Mar. 31, 2019	Jun. 30, 2022	Jun. 30, 2021
Revenue
Revenue accounted for under Topic 606		$ 9,191	$ 8,243			$ 17,211	$ 10,772
Product revenue, net
Revenue
Revenue accounted for under Topic 606		8,680	6,940			15,720	7,070
Collaboration revenue
Revenue
Revenue accounted for under Topic 606		96	813			725	2,815
Collaboration revenue | Sinovant Sciences, LTD | License Agreement
Revenue
Revenue accounted for under Topic 606							1,600
Collaboration revenue | Sumitomo Pharmaceuticals (Suzhou) | License Agreement
Revenue
Revenue accounted for under Topic 606						700
Collaboration revenue | Merck & Co | License Agreement
Revenue
Revenue accounted for under Topic 606							1,200
Collaboration revenue - Upfront payment | Sumitomo Pharmaceuticals (Suzhou) | License Agreement
Revenue
Revenue accounted for under Topic 606	$ 3,000			$ 1,000	$ 5,000
Research premium and grant revenue
Revenue
Revenue accounted for under Topic 606		$ 415	$ 490			$ 766	$ 887