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Note 1 - Summary of Significant Accounting Policies (Details Textual) - USD ($)		12 Months Ended		48 Months Ended
	Mar. 06, 2019	Dec. 31, 2019	Dec. 31, 2018	Mar. 09, 2014
Impairment of Deferred Development Costs		$ 0	$ 0
Asset Impairment Charges, Total		3,643,000	$ 0
Operating Lease, Expense		69,000
Lessee, Operating Lease, Liability, Payments, Due, Total		$ 43,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	25,000
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price	$ 5.20
Vested Annually [Member] \| Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage				20.00%
Minimum [Member]
Property, Plant and Equipment, Useful Life			3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life			40 years