Note 13 - Earnings Per Share - Reconciliation of Earnings (Loss) and the Weighted Average Number of Shares (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net (loss)/income available to the Company's common shareholders		$ (44,748)	$ 59,048	$ 780,537	$ 247,176
Earnings attributable to participating securities		(251)	(654)	(5,259)	(1,939)
Net (loss)/income available to the Company’s common shareholders for basic earnings per share		(44,999)	58,394	775,278	245,237
Distributions on convertible units		0	0	119	20
Net (loss)/income available to the Company’s common shareholders for diluted earnings per share		$ (44,999)	$ 58,394	$ 775,397	$ 245,257
Weighted average common shares outstanding – basic (in shares)		429,994	419,823	429,899	419,663
Equity awards (in shares)	[1]	0	1,120	1,496	1,273
Assumed conversion of convertible units (in shares)	[1]	0	59	207	50
Weighted average common shares outstanding – diluted (in shares)	[1]	429,994	421,002	431,602	420,986
Basic earnings per share (in dollars per share)		$ (0.10)	$ 0.14	$ 1.80	$ 0.58
Diluted earnings per share (in dollars per share)		$ (0.10)	$ 0.14	$ 1.80	$ 0.58

[1] The effect of the assumed conversion of certain convertible units had an anti-dilutive effect upon the calculation of Net income available to the Company’s common shareholders per share. Accordingly, the impact of such conversions has not been included in the determination of diluted earnings per share calculations. Additionally, there were 1.2 million and 0.5 million stock options that were not dilutive as of September 30, 2020 and 2019, respectively, and 2.5 million shares of restricted stock that were not dilutive for the three months ended September 30, 2020.