Note J - Common Stock and Warrants - Reserved Authorized Shares of Common Stock for Future Issuance (Details) - shares
Dec. 31, 2016
Dec. 31, 2015
Common shares reserved for future issuance (in shares) 12,114,618 7,124,961
Warrant [Member]    
Common shares reserved for future issuance (in shares) 2,087,477 2,325,383
Stock Compensation Plan [Member]    
Common shares reserved for future issuance (in shares) 1,990,260 1,397,511
Possible Future Issuances Under Equity Incentive Plans [Member]    
Common shares reserved for future issuance (in shares) 1,244,671 1,410,848
2021 Notes [Member]    
Common shares reserved for future issuance (in shares) 5,040,914
Convertible Notes Payable [Member]    
Common shares reserved for future issuance (in shares) 1,751,296 1,991,219