Note 3 - Procurement Contracts and Research Agreements (Details Textual) $ in Millions						3 Months Ended			12 Months Ended
	Sep. 28, 2022 USD ($)	May 12, 2022 USD ($)	Jan. 13, 2021 USD ($)	Apr. 03, 2020 USD ($)	Sep. 10, 2018 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jul. 31, 2019 USD ($)
Contract with Customer, Liability, Revenue Recognized									$ 2.9
The 19C BARDA Contract [Member]
Number of Courses to Be Delivered					1,488,000
Government Contract, Value of Award						$ 602.5			602.5
Government Contract, Base Period, Value of Award for Delivery and Support Activities					$ 51.7	51.7			$ 51.7
Base Period of Performance (Year)									5 years
Government Contract Value Related To Exercised Options									$ 268.9
Government Contract, Value, Payments Currently Specified as Unexercised Options									$ 281.9
Base Period of Performance, Exercise of Options, Term (Year)									10 years
Government Contract, Base Period, Value of Award for Delivery and Support Activities, Delivery of Courses					$ 11.1
Government Contract, Base Period, Number of Deliveries					35,700
Government Contract, Base Period, Value of Award for Delivery and Support Activities, Manufacture of Courses					$ 8.0
Government Contract, Base Period, Value of Award for Delivery and Support Activities, Advanced Development					32.0
Government Contract, Base Period, Value of Award for Delivery and Support Activities, Supportive Procurement Activities					$ 0.6
Proceeds from Delivery of Courses									$ 11.1
Number of Courses Delivered									35,700
Proceeds from Other Base Period Activities									$ 18.8
Government Contract, Value of Unexercised Options, Supportive Procurement Activities						5.6			5.6
The 19C BARDA Contract [Member] | Transferred over Time [Member]
Contract with Customer, Liability, Revenue Recognized									6.2	$ 4.8
The 19C BARDA Contract [Member] | Transferred at Point in Time [Member]
Contract with Customer, Liability, Revenue Recognized									7.2	112.5
The 19C BARDA Contract [Member] | IV TPOXX [Member]
Government Contract, Base Period, Number of Courses Manufactured					20,000
Government Contract Option Value Of Award For Delivery and Support Activities Manufacture of Courses											$ 10.2
Government Contract, Value, Payments Related to Exercised Options, Funding of Post-Marketing Activities						$ 3.6			$ 3.6
Number of Manufacturing Steps						2			2
The 19C BARDA Contract [Member] | IV BDS [Member]
Government Contract, Base Period, Value of Award for Delivery and Support Activities, Manufacture of Courses					$ 3.2
Proceeds from the Manufacture of Courses									$ 3.2
Proceeds from the Delivery of Courses									4.3
Contract with Customer, Liability, Total						$ 10.2			10.2	3.2
Government Contract, Value, Payments Currently Specified as Unexercised Options, Manufacture of Courses						20.5			20.5
Government Contract, Value of Courses Manufactured Upon Exercise of Options						$ 20.5			$ 20.5
Government Contract, Number of Options for Manufacture of Product						3			3
Government Contract, Courses Manufactured Upon Exercise of Options						64,000			64,000
The 19C BARDA Contract [Member] | IV FDP Containing IV BDS [Member]
Contract with Customer, Liability, Total						$ 0.3			$ 0.3
Contract with Customer, Liability, Revenue Recognized									2.9
The 19C BARDA Contract [Member] | Oral TPOXX [Member]
Government Contract, Base Period, Value of Award for Delivery and Support Activities, Manufacture of Courses									25.6
Number of Courses Delivered											726,140
Government Contract, Value, Payments Related to Exercised Options, Procurement of Raw Materials						225.1			225.1		$ 11.2
Government Contract, Value, Payments Related to Exercised Options, Delivery of Courses											213.9
Government Contract, Value, Payments Related to Exercised Options, Funding of Post-Marketing Activities											$ 14.6
Proceeds from Payments Received for Post-marketing Activities									7.3
Government Contract, Value, Payments Related to Unexercised Options, Delivery of Courses						225.1			225.1
The 19C BARDA Contract [Member] | IV FDP [Member]
Government Contract, Value, Payments Currently Specified as Unexercised Options, Manufacture of Courses						$ 51.2			$ 51.2
Government Contract, Number of Options for Manufacture of Product						3			3
Government Contract, Courses Manufactured Upon Exercise of Options						64,000			64,000
The 19C BARDA Contract [Member] | Maximum [Member]
Number of Courses to Be Delivered					212,000
U.S. Department of Defense (“DoD”) [Member] | Oral TPOXX [Member]
Government Contract, Value, Payments Currently Specified as Unexercised Options	$ 5.5	$ 3.8
Contract with Customer, Liability, Revenue Recognized								$ 3.6
Government Contract, Value Ordered	$ 5.2	$ 3.6
Government Contract, Value, Option Exercised							$ 3.8
International Procurement [Member]
Contract with Customer, Liability, Revenue Recognized									$ 71.0
International Procurement [Member] | Oral TPOXX [Member]
Government Contract, Value of Award						$ 77.0			77.0
Government Contract, Value, Payments Currently Specified as Unexercised Options						6.0
Contract with Customer, Liability, Revenue Recognized									71.0
International Procurement [Member] | Oral TPOXX [Member] | CANADA
Government Contract, Value of Award						39.0			39.0
International Procurement [Member] | Oral TPOXX [Member] | Europe, Asia Pacific and the Middle East [Member]
Government Contract, Value of Award						38.0			38.0
Meridian Contract [Member]
Contract with Customer, Liability, Revenue Recognized										12.7
Meridian Contract [Member] | Oral TPOXX [Member]
Government Contract, Value of Award			$ 33.0
Contract with Customer, Liability, Revenue Recognized							$ 35.0			10.0
Government Contract, Term (Year)			5 years
Government Contract, Increased Value of Award			$ 45.0
Canadian Contract [Member] | Meridian Medical Technologies [Member]
Contract with Customer, Liability, Revenue Recognized										4.0
Government Contract, Term (Year)				4 years
Other Commitment, Total				$ 14.0
Government Contract, Award, Target Delivery Amount						4.0			4.0
Government Contract, Unexercised Options									6.0
The PEP Label Expansion R & D Contract with the Department of Defense [Member]
Government Contract, Value of Award												$ 19.5
Contract with Customer, Liability, Revenue Recognized									17.9	$ 2.5
Government Contract, Increased Value of Award												27.0
Government Contract, Initial Award												$ 12.4
Contract With Customer Liability Remaining Revenue To Be Recognized						$ 6.4			$ 6.4