Note 1 - Interim Financial Statements - Reconciliation of Earnings (Loss) and the Weighted Average Number of Shares (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income from continuing operations		$ 165,578	$ 101,110	$ 280,836	$ 381,869
Gain on sale of operating properties, net of tax		39,268	26,499	66,164	58,554
Net income attributable to noncontrolling interests		(1,437)	(609)	(2,878)	(3,006)
Preferred stock dividends		(11,555)	(14,573)	(23,110)	(29,146)
Income from continuing operations available to the common shareholders		191,854	112,427	321,012	408,271
Earnings attributable to participating securities		(1,067)	(458)	(1,701)	(1,940)
Income from continuing operations attributable to common shareholders		190,787	111,969	319,311	406,331
Loss from discontinued operations					(75)
Net income attributable to the Company’s common shareholders for basic earnings per share		$ 190,787	$ 111,969	$ 319,311	$ 406,256
Weighted average common shares outstanding – basic (in shares)		417,748	411,317	415,189	411,057
Income from continuing operations (in dollars per share)		$ 0.46	$ 0.27	$ 0.77	$ 0.99
Loss from discontinued operations (in dollars per share)
Net income (in dollars per share)		$ 0.46	$ 0.27	$ 0.77	$ 0.99
Distributions on convertible units		$ 28	$ 139	$ 47	$ 373
Net income attributable to the Company’s common shareholders for diluted earnings per share		$ 190,815	$ 112,108	$ 319,358	$ 406,629
Equity awards (in shares)	[1]	1,457	1,103	1,450	1,281
Assumed conversion of convertible units (in shares)	[1]	97	666	93	810
Shares for diluted earnings per common share (in shares)		419,302	413,086	416,732	413,148
-Diluted (in dollars per share)		$ 0.46	$ 0.27	$ 0.77	$ 0.98
Loss from discontinued operations (in dollars per share)
Net income attributable to the Company (in dollars per share)		$ 0.46	$ 0.27	$ 0.77	$ 0.98

[1] For the three and six months ended June 30, 2016 and 2015, the effect of certain convertible units would have an anti-dilutive effect upon the calculation of Income from continuing operations per share. Accordingly, the impact of such conversion has not been included in the determination of diluted earnings per share calculations. At June 30, 2016 and 2015 the Company had outstanding stock options that were not dilutive of 5,108,530 and 6,802,560, respectively.