Note Q - Stockholders' Equity (Details Textual) - USD ($)		1 Months Ended							12 Months Ended			22 Months Ended
	Feb. 26, 2021	Nov. 30, 2022	Oct. 31, 2022	Sep. 30, 2022	Jul. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Jan. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2022	Feb. 28, 2020
Common Stock, Shares Authorized (in shares)									45,000,000	45,000,000		45,000,000
Preferred Stock, Shares Authorized (in shares)									5,000,000	5,000,000		5,000,000
Proceeds from Issuance of Common Stock									$ 1,238,000	$ 15,397,000	$ 39,203,000
Common Stock, Par or Stated Value Per Share (in dollars per share)									$ 0.001	$ 0.001		$ 0.001
Initial ATM Offering [Member] | Raymond James & Associates, Inc. [Member]
Common Stock, Maximum Amount to be Sold													$ 55,000,000
Stock Issued During Period, Shares, New Issues (in shares)								5,900,000
Shares Issued, Price Per Share (in dollars per share)								$ 9.12
Proceeds from Issuance of Common Stock								$ 53,900,000
Second ATM Offering [Member] | Raymond James & Associates, Inc. [Member]
Common Stock, Maximum Amount to be Sold	$ 35,000,000
Stock Issued During Period, Shares, New Issues (in shares)		29,426	313,333	94,491	6,740	34,686	65,748					544,424
Proceeds from Issuance of Common Stock		$ 80,000	$ 889,000	$ 269,000	$ 60,000	$ 310,000	$ 584,000					$ 2,192,000
Common Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.001
Agreement, Sales Agent Compensation, Percentage of Gross Sales	2.00%
Agreement, Maximum Reimbursement of Expenses in Connection with Registration of Shares	$ 10,000
Agreement, Maximum Reimbursement of Out-of-pocket Expenses	$ 30,000