Note 7 - Earnings Per Share - Earnings Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Basic weighted-average shares (in shares)	30,264,000	24,701,000	29,356,000	24,656,000
Conversion of unsecured loan notes (in shares)	0	0	0	0
Unexercised options and unvested RSUs (in shares)	71,000	419,000	126,000	0
Diluted weighted-average shares (in shares)	30,335,000	25,120,000	29,482,000	24,656,000