Note 7 - Leases (Details Textual)	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Jul. 31, 2019
Operating Lease, Weighted Average Discount Rate, Percent	9.80%		9.80%
Operating Lease, Weighted Average Remaining Lease Term (Year)	6 years 4 months 2 days		6 years 4 months 2 days
Lessee, Finance Lease, Number of Leases	0		0
Short-Term Lease Commitment, Amount	$ 0		$ 0
Operating Lease, Payments	$ 1,400,000	$ 970,000	$ 7,800,000	$ 2,800,000
Right of Use for Equipment with Initial Terms Exceeding One Year [Member]
Lessee, Operating Lease, Number of Right-of-Use Leases	7		7
Operating Lease Arrangements for Facilities [Member]
Lessee, Short-term Lease, Number of Leases	2		2
Lease Agreements for Manufacturing Equipment with Initial Terms of One Year or Less [Member]
Lessee, Short-term Lease, Number of Leases	1		1
South San Francisco Real Estate [Member]
Lessee, Operating Lease, Renewal Term (Year)	8 years		8 years		5 years
September 2021 Lease for Facility in South San Francisco [Member]
Lessee, Operating Lease, Renewal Term (Year)	8 years		8 years
Lessee, Operating Lease, Expected Tenant Improvements	$ 2,800,000		$ 2,800,000
Facility in South San Francisco [Member]
Lessee, Operating Lease, Renewal Term (Year)	5 years		5 years
Facility in Burlingame, California [Member]
Lessee, Short-term Lease, Number of Leases	2		2
Lessee, Operating Lease, Renewal Term (Year)	30 months		30 months
Lessee, Operating Lease, Number of Renewal Option	2		2