Note 8 - Leases (Details Textual) $ in Thousands	1 Months Ended			12 Months Ended
	Oct. 31, 2021 USD ($)	Oct. 31, 2019 USD ($)	Oct. 31, 2014 USD ($) ft²	Dec. 31, 2023 USD ($)		Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Feb. 28, 2019	Jan. 01, 2019 USD ($)	Apr. 30, 2018 USD ($)
Operating Lease, Right-of-Use Asset				$ 8,050		$ 8,888
Operating Lease, Liability				10,677	[1]	11,925
Operating Lease, Cost				$ 2,200		$ 2,700	$ 2,200
Operating Lease, Weighted Average Discount Rate, Percent								10.25%
The New Jersey Lease [Member]
Lessee, Operating Lease, Term of Contract (Year)		5 years
Average Annual Rental Payments		$ 300
The North Carolina Lease [Member]
Lessee, Operating Lease, Term of Contract (Year)	5 years
Average Annual Rental Payments	$ 200
Operating Lease, Weighted Average Discount Rate, Percent						5.65%
Minimum [Member]
Lessee, Operating Lease, Remaining Lease Term (Year)				2 years
Maximum [Member]
Lessee, Operating Lease, Remaining Lease Term (Year)				8 years
Revision of Prior Period, Adjustment [Member] | Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset									$ 9,500
Operating Lease, Liability									$ 8,100
Office Agreement with Fortress Biotech [Member]
Percentage of Occupancy			45.00%
Area of Real Estate Property (Square Foot) | ft²			24,000
Lessee, Operating Lease, Term of Contract (Year)			15 years
Average Annual Rental Payments			$ 1,800
Office Agreement [Member]
Operating Lease, Right-of-Use Asset				$ 8,100
Operating Lease, Liability				$ 10,700
Lessee, Operating Lease, Renewal Term (Year)				5 years
Long-Term Line of Credit			$ 600
Additional Collateral, Aggregate Fair Value										$ 600
Operating Lease, Weighted Average Remaining Lease Term (Year)				5 years 9 months 18 days
Operating Lease, Weighted Average Discount Rate, Percent				10.00%
Operating Lease, Payments, Use				$ 2,400

[1] As our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date and considering the term of the lease to determine the present value of lease payments. We used the incremental borrowing rate of 10.25% on February 28, 2019, for operating leases that commenced prior to that date through December 31, 2021. We used an incremental borrowing rate of 5.65% for the NC lease.