Revenue - Revenue from Collaborative Arrangements (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Janssen
Collaboration revenue recognized in the period from:
Revenue from collaborative arrangements	$ 2,788	$ 7,252	$ 8,621	$ 19,353
Other
Collaboration revenue recognized in the period from:
Revenue from collaborative arrangements	9	9	28	28
Collaborative revenue
Collaboration revenue recognized in the period from:
Revenue from collaborative arrangements	$ 2,797	$ 7,261	$ 8,649	$ 19,381