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
		Mar. 31, 2020	Mar. 31, 2019
Net income available to the Company's common shareholders		$ 83,746	$ 101,635
Earnings attributable to participating securities		(686)	(625)
Net income available to the Company’s common shareholders for basic earnings per share		83,060	101,010
Distributions on convertible units		0	25
Net income available to the Company’s common shareholders for diluted earnings per share		$ 83,060	$ 101,035
Weighted average common shares outstanding – basic (in shares)		429,735	419,464
Equity awards (in shares)	[1]	717	1,182
Assumed conversion of convertible units (in shares)	[1]	53	117
Weighted average common shares outstanding – diluted (in shares)	[1]	430,505	420,763
Basic earnings per share (in dollars per share)		$ 0.19	$ 0.24
Diluted earnings per share (in dollars per share)		$ 0.19	$ 0.24

[1] The effect of the assumed conversion of certain convertible units had an anti-dilutive effect upon the calculation of Income from continuing operations per share. Accordingly, the impact of such conversions has not been included in the determination of diluted earnings per share calculations. Additionally, there were 0.5 million, 1.3 million and 3.1 million stock options that were not dilutive as of December 31, 2019, 2018 and 2017, respectively.