Note 7 - Earnings Per Share - Earnings Per Share (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Basic weighted-average shares (in shares)	30,324,000	30,296,000	30,310,000	30,282,000
Conversion of unsecured loan notes (in shares)	0	0	0	0
Unexercised options and unvested RSUs (in shares)	0	0	0	0
Diluted weighted-average shares (in shares)	30,324,000	30,296,000	30,310,000	30,282,000