Significant Agreements (Details)	1 Months Ended				3 Months Ended		6 Months Ended		125 Months Ended	127 Months Ended
	Dec. 31, 2020 USD ($)	Oct. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Feb. 28, 2011 extension	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Sep. 01, 2021 USD ($)	Dec. 31, 2019 USD ($)	Jul. 26, 2019 USD ($)
Long-term Purchase Commitment
Total revenues					$ 391,000	$ 1,402,000	$ 1,826,000	$ 2,643,000
SymBio Pharmaceuticals
Long-term Purchase Commitment
Total revenues		$ 5,000,000.0
BARDA
Long-term Purchase Commitment
Number of extension periods | extension				4
Total revenues					$ 300,000	$ 1,400,000	$ 1,500,000	$ 2,600,000	$ 77,000,000.0
Cantex Pharmaceuticals Inc.
Long-term Purchase Commitment
Payments to be made for regulatory milestones (up to)												$ 202,500,000
Payments to be made upon achievement of specified net sales levels (up to)												$ 385,000,000.0
Royalty percentage to be paid (at least)												10.00%
SymBio Pharmaceuticals
Long-term Purchase Commitment
Total revenues			$ 5,000,000.0
Termination notice period			90 days
Payment to be received upon achievement of milestones			$ 180,000,000.0
Ohara Pharmaceutical Co., Ltd.
Long-term Purchase Commitment
License agreement, nonrefundable regulatory milestone payment to be received											$ 2,500,000
CR Sanjui | Oncoceutics, Inc.
Long-term Purchase Commitment
Total revenues	$ 5,000,000.0
Scenario, Forecast | BARDA
Long-term Purchase Commitment
Total revenues										$ 78,900,000
Scenario, Forecast | BARDA | Expense reimbursement
Long-term Purchase Commitment
Total revenues										75,800,000
Scenario, Forecast | BARDA | Fees
Long-term Purchase Commitment
Total revenues										5,300,000
Scenario, Forecast | BARDA Fourth Option Segment
Long-term Purchase Commitment
Total revenues										$ 4,600,000