The Business and Summary of Significant Accounting Policies - Narrative (Details) $ in Thousands		3 Months Ended		6 Months Ended
	Sep. 26, 2022 USD ($) treatment	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) segment	Jun. 30, 2023 USD ($)	Dec. 31, 2019 USD ($)
Business and Summary of Significant Accounting Policies
Contract and grant revenue		$ 129	$ 26	$ 129	$ 309
Number of segment | segment				1
Grant | Oncoceutics, Inc.
Business and Summary of Significant Accounting Policies
Deferred revenue		100		$ 100
Contract and grant revenue		100	0	100	30
Licensing
Business and Summary of Significant Accounting Policies
Contract and grant revenue		0	0	0	49
SymBio Pharmaceuticals | Scenario, Plan
Business and Summary of Significant Accounting Policies
Deferred revenue	$ 12,500
Emergent Biodefense Operations Lansing LLC
Business and Summary of Significant Accounting Policies
Revenue recognized		0	26	0	200
Ohara Pharmaceutical Co., Ltd.
Business and Summary of Significant Accounting Policies
License agreement, nonrefundable regulatory milestone payment to be received						$ 2,500
Ohara Pharmaceutical Co., Ltd. | Licensing
Business and Summary of Significant Accounting Policies
Contract and grant revenue		$ 0	$ 0	$ 0	$ 100
Base Period | Emergent | TEMBEXA
Business and Summary of Significant Accounting Policies
Up-front cash payment	$ 238,000
Quantity royalty rate, trigger (treatments) | treatment	1,700,000
Base Period | Emergent | TEMBEXA | Non- United States
Business and Summary of Significant Accounting Policies
Gross profit royalty rate (as a percent)	15.00%
Base Period | Emergent | TEMBEXA | United States
Business and Summary of Significant Accounting Policies
Gross profit royalty rate (as a percent)	20.00%
Base Period | Emergent | BARDA
Business and Summary of Significant Accounting Policies
Maximum milestone proceeds upon the exercise of options	$ 124,000