Revenue - Reimbursement of R and D Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Research and Development Reimbursement
Total reduction to R and D expense	$ 1,914	$ 815	$ 4,392	$ 2,429
Janssen
Research and Development Reimbursement
Total reduction to R and D expense	1,563	784	2,770	2,195
Mylan
Research and Development Reimbursement
Total reduction to R and D expense	$ 351	$ 31	$ 1,622	$ 234