Sinovant License Agreement (Details) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2018 USD ($) item	Mar. 31, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) item	Jun. 30, 2017 USD ($)
License Agreement
Revenue	$ 847		$ 1,051	$ 8,398	$ 2,729
Sinovant Sciences, LTD | License Agreement
License Agreement
Notice period for termination of agreement				180 days
Number of deliverables | item	2			2
Sinovant Sciences, LTD | License Agreement | Achievement of certain regulatory and commercial milestones
License Agreement
Maximum contingent milestone payment	$ 91,500			$ 91,500
Sinovant Sciences, LTD | License Agreement | Subsequent regulatory approval
License Agreement
Maximum contingent milestone payment	$ 4,000			4,000
Collaboration revenue - Upfront payment | Sinovant Sciences, LTD | License Agreement
License Agreement
Revenue		$ 5,000
Collaboration revenue - Variable consideration | Sinovant Sciences, LTD | License Agreement | Clinical trial application submission
License Agreement
Revenue				$ 1,500