Note K - Common Stock and Warrants - Reserved Authorized Shares of Common Stock for Future Issuance (Details) - shares	Dec. 31, 2019	Dec. 31, 2018
Common shares reserved for future issuance (in shares)	48,267,688	13,641,913
Series A Preferred Stock [Member]
Common shares reserved for future issuance (in shares)		1,112,334
Warrant [Member]
Common shares reserved for future issuance (in shares)	2,423,077	2,527,763
Share-based Payment Arrangement [Member]
Common shares reserved for future issuance (in shares)	5,192,222	3,704,755
Possible Future Issuances under the Prior Purchase Agreement [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)	84,616	648,272
2021 Notes [Member]
Common shares reserved for future issuance (in shares)	175,336	4,481,182
The 2019 Notes [Member]
Common shares reserved for future issuance (in shares)	3,186,770
Optional Exchange Principal Amount [Member]
Common shares reserved for future issuance (in shares)	26,439,015
Convertible Notes Payable [Member]
Common shares reserved for future issuance (in shares)	1,213,606	1,167,607