Note H - Fair Value of Financial Instruments - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($)	Mar. 31, 2022	Dec. 31, 2021
Fair Value, Recurring [Member]
Total assets	$ 18,902,000	$ 15,422,000
Fair Value, Recurring [Member] | US Government Agencies Debt Securities [Member]
Total assets	7,335,000	4,997,000
Fair Value, Recurring [Member] | Corporate Debt Securities [Member]
Total assets	1,338,000
Fair Value, Recurring [Member] | Certificates of Deposit [Member]
Total assets	481,000	490,000
Fair Value, Recurring [Member] | US Treasury Securities [Member]
Total assets	9,748,000	9,935,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Total assets	10,229,000	10,425,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Government Agencies Debt Securities [Member]
Total assets	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate Debt Securities [Member]
Total assets	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Certificates of Deposit [Member]
Total assets	481,000	490,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Treasury Securities [Member]
Total assets	9,748,000	9,935,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Total assets	8,673,000	4,997,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Government Agencies Debt Securities [Member]
Total assets	7,335,000	4,997,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member]
Total assets	1,338,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Certificates of Deposit [Member]
Total assets	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Treasury Securities [Member]
Total assets	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Total assets	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | US Government Agencies Debt Securities [Member]
Total assets	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate Debt Securities [Member]
Total assets	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Certificates of Deposit [Member]
Total assets	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | US Treasury Securities [Member]
Total assets	0	0
Deerfield Warrant Liability [Member]
Financial liabilities measured at fair value on recurring basis	80,000	288,000
Deerfield Warrant Liability [Member] | Fair Value, Recurring [Member]
Financial liabilities measured at fair value on recurring basis	80,000	288,000
Deerfield Warrant Liability [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial liabilities measured at fair value on recurring basis	0	0
Deerfield Warrant Liability [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities measured at fair value on recurring basis	0	0
Deerfield Warrant Liability [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Financial liabilities measured at fair value on recurring basis	80,000	288,000
Embedded Put Option [Member]
Financial liabilities measured at fair value on recurring basis	4,000	18,000
Embedded Put Option [Member] | Fair Value, Recurring [Member]
Financial liabilities measured at fair value on recurring basis	4,000	18,000
Embedded Put Option [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial liabilities measured at fair value on recurring basis	0	0
Embedded Put Option [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities measured at fair value on recurring basis	0	0
Embedded Put Option [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Financial liabilities measured at fair value on recurring basis	4,000	18,000
KVK Warrant Liability [Member] | Fair Value, Recurring [Member]
Financial liabilities measured at fair value on recurring basis	5,000	24,000
KVK Warrant Liability [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial liabilities measured at fair value on recurring basis	0	0
KVK Warrant Liability [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities measured at fair value on recurring basis	5,000	24,000
KVK Warrant Liability [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Financial liabilities measured at fair value on recurring basis	0	0
Optional Exchange Principal Amount Conversion Feature [Member[ | Fair Value, Recurring [Member]
Financial liabilities measured at fair value on recurring basis	89,000	330,000
Optional Exchange Principal Amount Conversion Feature [Member[ | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial liabilities measured at fair value on recurring basis	0	0
Optional Exchange Principal Amount Conversion Feature [Member[ | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities measured at fair value on recurring basis	5,000	24,000
Optional Exchange Principal Amount Conversion Feature [Member[ | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Financial liabilities measured at fair value on recurring basis	$ 84,000	$ 306,000