Note 14 - 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, 2019	Mar. 31, 2018
Net income available to the Company's common shareholders		$ 101,635	$ 129,501
Earnings attributable to participating securities		(625)	(599)
Net income available to the Company’s common shareholders for basic earnings per share		101,010	128,902
Distributions on convertible units		25	244
Net income available to the Company’s common shareholders for diluted earnings per share		$ 101,035	$ 129,146
Weighted average common shares outstanding – basic (in shares)		419,464	423,404
Effect of dilutive securities (1):
Equity awards (in shares)	[1]	1,182	287
Assumed conversion of convertible units (in shares)	[1]	117	830
Weighted average common shares outstanding – diluted (in shares)	[1]	420,763	424,521
Basic earnings per share (in dollars per share)		$ 0.24	$ 0.30
Diluted earnings per share (in dollars per share)		$ 0.24	$ 0.30

[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 1.3 million and 3.3 million stock options that were not dilutive as of March 31, 2019 and 2018, respectively.