Note N - Net Loss Per Share - Anti-dilutive Securities (Details) - shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Series A (in shares) 10,869,947 5,714,113 10,430,981
Warrants to Purchase Common Stock [Member]      
Series A (in shares) 2,087,477 2,325,383 595,920
Deerfield Warrant to Purchase Series D Preferred Stock [Member]      
Series A (in shares) 2,066,970
Stock Compensation Plan [Member]      
Series A (in shares) 1,990,260 1,397,511 395,185
Convertible Debt Securities [Member]      
Series A (in shares) 1,751,296 1,991,219 1,808,353
2021 Notes [Member]      
Series A (in shares) 5,040,914
Series A Redeemable Convertible Preferred Stock [Member]      
Series A (in shares) 1,293,838
Series B Redeemable Convertible Preferred Stock [Member]      
Series A (in shares) 829,234
Series C Redeemable Convertible Preferred Stock [Member]      
Series A (in shares) 2,474,122
Series D Redeemable Convertible Preferred Stock [Member]      
Series A (in shares) 967,359
Redeemable Convertible Preferred Stock [Member]      
Series A (in shares) 5,564,553