Note N - Equity - Summary of Warrant Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Total warrants (in shares)	1,398,969	1,260,080
Weighted average exercise price (in dollars per share)	$ 3.81	$ 3.84
Weighted average remaining contractual life (Year)	2 years 18 days	2 years 21 days	2 years 284 days
Granted (in shares)	1,035,000	138,889
Granted, weighted average exercise price (in dollars per share)	$ 1.50	$ 3.60
Exercised (in shares)
Exercised, weighted average exercise price (in dollars per share)
Forfeited (in shares)
Forfeited, weighted average exercise price (in dollars per share)
Expired (in shares)	(145,841)
Expired, weighted average exercise price (in dollars per share)	$ 6
Total warrants (in shares)	3,780,976	1,398,969	1,260,080
Weighted average exercise price (in dollars per share)	$ 1.59	$ 3.81	$ 3.84
Increase due to trigger of anti-dilution provision feature (in shares)	1,492,848
Increase due to trigger of anti-dilution provision feature (in dollars per share)	$ 1.50
Vested or expected to vest at December 31, 2018 (in shares)	3,780,976
Vested or expected to vest at December 31, 2018 (in dollars per share)	$ 1.59
Vested or expected to vest at December 31, 2018 (Year)	2 years 18 days
Exercisable at December 31, 2018 (in shares)	3,780,976
Exercisable at December 31, 2018 (in dollars per share)	$ 1.59
Exercisable at December 31, 2018 (Year)	2 years 18 days