Note 5 - Balance Sheet Components (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Interest Receivable	$ 100,000	$ 200,000
Accounts Receivable, after Allowance for Credit Loss, Current	3,008,000	20,000
Accounts Receivable, Allowance for Credit Loss, Current	0	0
Depreciation, Total	3,800,000	2,000,000
Tangible Asset Impairment Charges, Total	0	0
Operating Lease, Right-of-Use Asset	24,840,000	25,715,000
Amortization of Intangible Assets	700,000	1,300,000
Goodwill, Ending Balance	4,508,000	4,508,000
Goodwill, Impairment Loss	$ 0	0
Developed Technology Rights [Member]
Finite-Lived Intangible Asset, Remaining Life (Year)	5 years 10 months 24 days
Impairment of Intangible Assets (Excluding Goodwill), Total		4,300,000
Intellectual Property [Member]
Finite-Lived Intangible Asset, Remaining Life (Year)	4 years
Facility in Burlingame, California [Member]
Operating Lease, Right-of-Use Asset	$ 3,100,000	15,000,000
Royalty [Member]
Accounts Receivable, after Allowance for Credit Loss, Current	$ 3,000,000	$ 20,000