Note 2 - Significant Accounting Policies and Basis of Presentation (Details Textual) - USD ($) shares in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jan. 01, 2019
Cost Reimbursements from SBIR Grant as Offset to Research and Development Expenses	$ 280,000	$ 175,000
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0.6	0.5
Lessee, Operating Lease, Liability, Payments, Due, Total	$ 19,800
Operating Lease, Payments	$ 59,500
Lessee, Operating Lease, Discount Rate	12.75%
Operating Leases, Rent Expense, Net, Total	$ 117,900	$ 108,300
Operating Leases, Rent Expense, Sublease Rentals	27,100
Sublease Income	59,100
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset			$ 53,000
Operating Lease, Liability, Total			$ 75,700
Short-term Leases [Member]
Operating Leases, Rent Expense, Net, Total	57,500
Other Noncurrent Assets [Member]
Operating Lease, Right-of-Use Asset	13,900
Other Current Liabilities [Member]
Operating Lease, Liability, Total	$ 19,500
Minimum [Member]
Lessee, Operating Lease, Term of Contract	1 year