Note 1 - Significant Accounting Policies - Schedule of Antidilutive Securities (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Antidilutive securities excluded from calculation of earnings per share (in shares)	45,653	1,511,420	195,954
Restricted Stock Units (RSUs) [Member]
Antidilutive securities excluded from calculation of earnings per share (in shares)	45,653	1,400,950	175,752
Performance Shares [Member]
Antidilutive securities excluded from calculation of earnings per share (in shares)	0	110,470	20,202