Note 1 - Summary of Significant Accounting Policies (Detail) - Reconciliation Of Earnings/(Loss) And The Weighted Average Number Of Shares (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Income from continuing operations									$ 211,978		$ 158,977		$ 120,122
Total net gain on transfer or sale of operating properties, net											12,074		2,080
Net income attributable to noncontrolling interests									(14,202)		(13,039)		(18,783)
Discontinued operations attributable to noncontrolling interests									1,731		1,384		5,288
Preferred stock redemption costs									(21,703)
Preferred stock dividends									(71,697)		(59,363)		(51,346)
Income from continuing operations available to the common shareholders									110,406		88,067		57,658
Earnings attributable to unvested restricted shares									(1,221)		(608)		(375)
Income from continuing operations attributable to common shareholders									109,185		87,459		57,283
Income from discontinued operations attributable to the Company									62,267		21,621		33,864
Net income attributable to the Company’s common shareholders for basic earnings per share									171,452		109,080		91,147
Weighted average common shares outstanding (in Shares)									405,997		406,530		405,827
Income from continuing operations (in Dollars per share)									$ 0.27		$ 0.22		$ 0.14
Income from discontinued operations (in Dollars per share)									$ 0.15		$ 0.05		$ 0.08
Net income (in Dollars per share)	$ 0.14	$ 0.07	$ 0.12	$ 0.09	$ 0.08	$ 0.10	$ 0.06	$ 0.03	$ 0.42		$ 0.27		$ 0.22
Income from continuing operations attributable to common shareholders									109,185		87,459		57,283
Income from discontinued operations attributable to the Company									62,267		21,621		33,864
Net income attributable to common shareholders for diluted earnings per share									171,452		109,080		91,147
Weighted average common shares outstanding – basic (in Shares)									405,997		406,530		405,827
Equity awards (in Shares)									692	[1]	1,139	[1]	374	[1]
Shares for diluted earnings per common share (in Shares)									406,689		407,669		406,201
Income from continuing operations (in Dollars per share)									$ 0.27		$ 0.21		$ 0.14
Income from discontinued operations (in Dollars per share)									$ 0.15		$ 0.06		$ 0.08
Net income (in Dollars per share)	$ 0.14	$ 0.07	$ 0.12	$ 0.09	$ 0.08	$ 0.10	$ 0.06	$ 0.03	$ 0.42		$ 0.27		$ 0.22
Operating Properties [Member]
Total net gain on transfer or sale of operating properties, net									$ 4,299		$ 108		$ 2,377

[1] The effect of the assumed conversion of certain convertible units had an anti-dilutive effect upon the calculation of Income/(loss) from continuing operations per share. Accordingly, the impact of such conversions has not been included in the determination of diluted earnings per share calculations