Collaboration Agreements - Shenyang Sunshine Pharmaceutical Co., Ltd (Narrative) (Details) - 3SBio License - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	May 31, 2014
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Aggregate amount of upfront and milestone-based payments			$ 3.0
License fees due under agreement		$ 4.0
Aggregate amount for future payments upon achievement of clinical and regulatory approval milestones for products containing ImmTOR platform	$ 17.0
Aggregate amount for future payments upon achievement of clinical and regulatory approval milestones for products without ImmTOR Platform	$ 41.5