Note K - Common Stock and Warrants (Details Textual) - USD ($)						4 Months Ended	12 Months Ended			15 Months Ended	23 Months Ended
	Sep. 03, 2019	Oct. 25, 2018	Oct. 10, 2018	Oct. 05, 2018	Jun. 02, 2014	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2013	Dec. 31, 2019	Sep. 04, 2018	Dec. 31, 2017
Common Stock, Shares Authorized						250,000,000	250,000,000	250,000,000		250,000,000
Common Stock, Shares, Issued, Total						36,350,785	36,350,785	26,455,352		36,350,785
Proceeds from Issuance of Common Stock								$ 4,828,000
Stock Issued During Period, Shares, Conversion of Convertible Securities								598,568
Common Stock, Shares, Outstanding, Ending Balance						36,350,785	36,350,785	26,455,352		36,350,785		14,657,430
Common Stock [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights									143,466
Class of Warrant or Right, Exercise Price of Warrants or Rights									$ 5.85
2013 Warrants [Member]
Debt Instrument, Face Amount									$ 3,800,000
Class of Warrant or Right Issued									1,079,453
Series D Redeemable Convertible Preferred Stock [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights									1,079,453
Deerfield Warrant [Member]
Class of Warrant or Right Issued					14,423,076
Deerfield Warrant [Member] | Common Stock [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights					1,923,077
Class of Warrant or Right, Exercise Price of Warrants or Rights					$ 5.85
Warrant Issued to KVK [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights		500,000
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 2.30
Class of Warrant or Right, Additional Shares Exercisable for Each Milestones		125,000
Series A Preferred Stock Converted Into Common Stock [Member]
Conversion of Stock, Shares Converted										9,577
Conversion of Stock, Shares Issued							1,112,333	2,080,000		3,192,333
2021NotesConvertedToCommonStockMember
Stock Issued During Period, Shares, Conversion of Convertible Securities	1,499,894
2021NotesConvertedToSeriesB1PreferredStockMember
Stock Issued During Period, Shares, Conversion of Convertible Securities	1,576
Series B-1 Preferred Convertible Stock Converted to Common Stock [Member]
Conversion of Stock, Shares Converted						1,576	1,576
Conversion of Stock, Shares Issued						1,659,966	1,659,996
Exchanged 2021 Notes for Series A Preferred Stock [Member]
Debt Conversion, Converted Instrument, Shares Issued				9,577
Second ATM Agreement [Member]
Stock Issued During Period, Shares, New Issues							0
Cowen and Company, LLC [Member]
Stock Issued During Period, Shares, New Issues											762,338
Proceeds from Issuance of Common Stock											$ 4,900,000
RBC Capital Markets, LLC [Member] | Underwriting Agreement [Member]
Stock Issued During Period, Shares, New Issues			8,333,334	8,333,334