Note 1 - Basis of Presentation - Schedule of Antidilutive Securities (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Antidilutive securities excluded from calculation of earnings per share (in shares)	42,321	1,546,018	51,101	1,288,649
Restricted Stock Units (RSUs) [Member]
Antidilutive securities excluded from calculation of earnings per share (in shares)	42,321	1,516,956	51,101	1,259,588
Performance Shares [Member]
Antidilutive securities excluded from calculation of earnings per share (in shares)	0	29,062	0	29,061