Note 1 - Basis of Presentation - Schedule of Antidilutive Securities (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Antidilutive securities excluded from calculation of earnings per share (in shares)	1,062,343	1,590,914	1,152,797	1,393,813
Restricted Stock Units (RSUs) [Member]
Antidilutive securities excluded from calculation of earnings per share (in shares)	983,708	1,561,852	1,063,253	1,361,077
Performance Shares [Member]
Antidilutive securities excluded from calculation of earnings per share (in shares)	78,635	29,062	89,544	32,736