Note 21 - Incentive Plans - Performance Shares Activity (Details) - Performance Shares [Member] - shares		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restricted stock outstanding as of January 1, (in shares)		704,530	433,230	235,950
Granted (1) (in shares)	[1]	506,720	407,080	297,450
Vested (in shares)	[2]	(297,450)	(135,780)	(100,170)
Restricted stock outstanding as of December 31, (in shares)		913,800	704,530	433,230

[1] The weighted-average grant date fair value for performance shares issued during the years ended December 31, 2020, 2019 and 2018 were $18.02, $22.00 and $15.40, respectively.

[2] For the years ended December 31, 2020, 2019 and 2018, the corresponding common stock equivalent of these vested awards were 594,900, 104,551 and 0 shares, respectively.