Sale of Intellectual Property	12 Months Ended
Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Sale of Intellectual Property	9. Sale of Intellectual Property In April, 2017 the Company entered into an agreement to sell certain oncology assets and patents to Fosun. Fosun paid the Company a one-time nonrefundable payment of $0.6 million net of taxes in June 2017 and is required to pay royalties on net sales of products by Fosun and its affiliates and other consideration based on revenues from any licensees. The Company accounted for the transaction as a sale of assets. The Company recorded the $0.6 million in payments received in revenue – other during the second quarter of 2017 as the Company had performed substantially all of its obligations as of June 30, 2017. The royalties and other consideration referred to above represent variable consideration for which the Company has not recognized any revenue because it is uncertain whether and in what period Fosun will be able to sublicense this technology or have the ability to develop, manufacture or sell product utilizing this technology. Therefore receipt of such payments is highly susceptible to factors outside the Company’s influence, the uncertainty regarding the receipt of these payments is not expected to be resolved for years, and the Company has limited experience with similar contracts.

Sale of Intellectual Property

12 Months Ended

Dec. 31, 2018

Goodwill And Intangible Assets Disclosure [Abstract]

9. Sale of Intellectual Property

In April, 2017 the Company entered into an agreement to sell certain oncology assets and patents to Fosun. Fosun paid the Company a one-time nonrefundable payment of $0.6 million net of taxes in June 2017 and is required to pay royalties on net sales of products by Fosun and its affiliates and other consideration based on revenues from any licensees. The Company accounted for the transaction as a sale of assets. The Company recorded the $0.6 million in payments received in revenue – other during the second quarter of 2017 as the Company had performed substantially all of its obligations as of June 30, 2017. The royalties and other consideration referred to above represent variable consideration for which the Company has not recognized any revenue because it is uncertain whether and in what period Fosun will be able to sublicense this technology or have the ability to develop, manufacture or sell product utilizing this technology. Therefore receipt of such payments is highly susceptible to factors outside the Company’s influence, the uncertainty regarding the receipt of these payments is not expected to be resolved for years, and the Company has limited experience with similar contracts.