Note 2 - Basis of Presentation and Summary of Significant Accounting Policies - Estimated Useful Lives for Major Asset Categories (Details)	12 Months Ended
	Dec. 31, 2019
Lab and Build-to-Suit Equipment [Member] | Minimum [Member]
Property, Plant and Equipment, Useful life (Year)	5 years
Lab and Build-to-Suit Equipment [Member] | Maximum [Member]
Property, Plant and Equipment, Useful life (Year)	7 years
Office Equipment [Member]
Property, Plant and Equipment, Useful life (Year)	5 years
Furniture and Fixtures [Member]
Property, Plant and Equipment, Useful life (Year)	10 years
Computer Equipment [Member]
Property, Plant and Equipment, Useful life (Year)	3 years
Leasehold Improvements [Member]
Property, Plant and Equipment, Estimated Useful life	Lesser of life of the asset or remaining lease term