Note 17 - 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, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net income available to the Company's common shareholders		$ 85,624	$ 101,957	$ 365,977	$ 298,996
Change in estimated redemption value of redeemable noncontrolling interests		(3,918)		(3,918)
Earnings attributable to participating securities		(604)	(526)	(1,818)	(1,596)
Net income available to the Company’s common shareholders for basic earnings per share		81,102	101,431	360,241	297,400
Distributions on convertible units			24	683	43
Net income available to the Company’s common shareholders for diluted earnings per share		$ 81,102	$ 101,455	$ 360,924	$ 297,443
Weighted average common shares outstanding – basic (in shares)		419,230	423,688	421,106	423,574
Effect of dilutive securities (1):
Equity awards (in shares)	[1]	534	513	515	556
Assumed conversion of convertible units (in shares)	[1]		110	822	63
Weighted average common shares outstanding – diluted (in shares)	[1]	419,764	424,311	422,443	424,193
Basic earnings per share (in dollars per share)		$ 0.19	$ 0.24	$ 0.86	$ 0.70
Diluted earnings per share (in dollars per share)		$ 0.19	$ 0.24	$ 0.85	$ 0.70

[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 1.3 million and 2.3 million stock options that were not dilutive as of September 30, 2018 and 2017, respectively.