Revenue - Janssen Biotech Agreement (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	Feb. 28, 2018	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Collaborative Arrangements and Co-Promote Agreement
Revenues		$ 14,946	$ 13,194	$ 12,914	$ 14,257	$ 18,730	$ 18,257	$ 15,008	$ 19,862	$ 55,311	$ 71,857	$ 73,414
Percentage of profit share	33.00%									35.00%
Revenue from collaborative arrangements										$ 11,463	26,464	31,245
Research and development										193,657	260,953	219,248
Janssen
Collaborative Arrangements and Co-Promote Agreement
Upfront payment receivable	$ 100,000									100,000
Percentage of profit share	67.00%
Revenue from collaborative arrangements										11,425	26,426	31,096
Research and development										$ 18,300	$ 38,500	$ 39,900
Janssen | Collaborative Arrangement
Collaborative Arrangements and Co-Promote Agreement
Upfront payment receivable	$ 100,000
Janssen | Collaborative Arrangement | Izencitinib
Collaborative Arrangements and Co-Promote Agreement
Collaborative arrangement, opt in fee	$ 200,000