Note 7 - Property, Plant and Equipment - Property, Plant and Equipment (Details) - USD ($)	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Dec. 31, 2017
Total property, plant and equipment	$ 20,587,077		$ 17,435,430
Accumulated depreciation and amortization	(11,333,112)		(9,304,722)
Property, plant and equipment, net	9,253,965	$ 8,022,974	8,130,708
Lab and Build-to-Suit Equipment [Member]
Total property, plant and equipment	7,562,263		7,266,895
Office Equipment [Member]
Total property, plant and equipment	128,669		130,460
Furniture and Fixtures [Member]
Total property, plant and equipment	237,951		205,051
Computer Equipment [Member]
Total property, plant and equipment	804,046		799,515
Leasehold Improvements [Member]
Total property, plant and equipment	11,762,351		8,878,361
Construction in Progress [Member]
Total property, plant and equipment	$ 91,797		$ 155,148	$ 2,830,407