Note 4 - Common Stock (Details Textual) - shares	Dec. 31, 2023	Dec. 31, 2022
Common Stock, Shares, Issued (in shares)	31,361,303	31,272,303
Common Stock, Shares, Outstanding (in shares)	30,385,297	30,296,297
Reserved For Issuance Upon Exercise Or Vesting Of Equity Awards [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)	5,600,676
Reserved For Issuance Upon Exercise Or Vesting Of Equity Awards [Member] | Share-Based Payment Arrangement, Option [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)	270,500
NIL Coupon Non-redeemable Convertible Unsecured Loan Notes [Member] | Unsecured Debt [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)	6,715