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		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income/(loss) from continuing operations		$ (51,319)	$ 53,419	$ 229,517	$ 435,288
Gain on sale of operating properties, net of tax		9,771	27,665	75,935	86,219
Net income attributable to noncontrolling interests		(1,997)	(3,512)	(4,875)	(6,518)
Preferred stock dividends		(11,555)	(14,573)	(34,665)	(43,719)
Income/(loss) from continuing operations available to the common shareholders		(55,100)	62,999	265,912	471,270
Earnings attributable to participating securities		(502)	(405)	(1,493)	(2,178)
Income/(loss) from continuing operations attributable to common shareholders		(55,602)	62,594	264,419	469,092
Loss from discontinued operations attributable to the Company					(75)
Net income/(loss) attributable to the Company’s common shareholders for basic earnings per share		$ (55,602)	$ 62,594	$ 264,419	$ 469,017
Weighted average common shares outstanding – basic (in shares)		420,073	411,487	416,829	411,202
Income/(loss) from continuing operations (in dollars per share)		$ (0.13)	$ 0.15	$ 0.63	$ 1.14
Loss from discontinued operations (in dollars per share)
-Basic (in dollars per share)		$ (0.13)	$ 0.15	$ 0.63	$ 1.14
Distributions on convertible units					$ 446
Net income/(loss) attributable to the Company’s common shareholders for diluted earnings per share		$ (55,602)	$ 62,594	$ 264,419	$ 469,463
Equity awards (in shares)	[1]		1,199	1,405	1,337
Assumed conversion of convertible units (in shares)	[1]				723
Shares for diluted earnings per common share (in shares)		420,073	412,686	418,234	413,262
Income/(loss) from continuing operations (in dollars per share)		$ (0.13)	$ 0.15	$ 0.63	$ 1.14
Loss from discontinued operations (in dollars per share)
-Diluted (in dollars per share)		$ (0.13)	$ 0.15	$ 0.63	$ 1.14

[1] For the three and nine months ended September 30, 2016 and 2015, the effect of certain convertible units would have an anti-dilutive effect upon the calculation of Income/(loss) 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 September 30, 2016 and 2015, the Company had outstanding stock options that were not dilutive of 3,545,000 and 5,963,010, respectively.