Note I - Net (Loss) Income Per Share - Anti-dilutive Securities (Details) - shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Antidilutive securities (in shares)	11,692,856	11,102,315
Warrants to Purchase Common Stock [Member]
Antidilutive securities (in shares)	2,027,763	2,087,477
Stock Compensation Plan [Member]
Antidilutive securities (in shares)	2,872,769	2,222,628
Convertible Debt Securities [Member]
Antidilutive securities (in shares)	1,751,410	1,751,296
2021 Notes [Member]
Antidilutive securities (in shares)	5,040,914	5,040,914