Note F - Common Stock and Warrants - Reserved Authorized Shares of Common Stock for Future Issuance (Details) - shares		Sep. 30, 2020	Dec. 31, 2019
Common shares reserved for future issuance (in shares)		20,562,937	48,267,688
Warrant [Member]
Common shares reserved for future issuance (in shares)		2,423,077	2,423,077
Share-based Payment Arrangement [Member]
Common shares reserved for future issuance (in shares)		5,670,659	5,192,222
Possible Future Issuances Under the Equity Line of Credit [Member]
Common shares reserved for future issuance (in shares)			9,553,046
Possible Future Issuances Under Equity Incentive Plans [Member]
Common shares reserved for future issuance (in shares)		803,698	84,616
2021 Notes [Member]
Common shares reserved for future issuance (in shares)			175,336
January 2020 Note [Member]
Common shares reserved for future issuance (in shares)		544,599
The 2019 Notes [Member]
Common shares reserved for future issuance (in shares)		9,844,933	3,186,770
Optional Exchange Principal Amount [Member]
Common shares reserved for future issuance (in shares)	[1]		26,439,015
Convertible Notes Payable [Member]
Common shares reserved for future issuance (in shares)		1,275,971	1,213,606

[1] Common Stock issuable (i) in exchange of the Deerfield Optional Conversion Feature, or (ii) upon conversion of the Series B-2 Preferred Stock issuable in exchange of the Deerfield Optional Conversion Feature