Revenue - Revenue from Collaborative Arrangements (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Collaboration revenue recognized in the period from:
Revenue from collaborative arrangements	$ 5,488	$ 7,493	$ 12,120	$ 12,825
Janssen
Collaboration revenue recognized in the period from:
Revenue from collaborative arrangements	5,479	7,392	12,101	12,715
Other
Collaboration revenue recognized in the period from:
Revenue from collaborative arrangements	9	101	19	116
Collaborative revenue
Collaboration revenue recognized in the period from:
Revenue from collaborative arrangements	$ 5,488	$ 7,493	$ 12,120	$ 12,831