Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Continuing Operations [Member]
Operating expenses
Impairment charges	$ 5,840	$ 6,391
Joint Ventures [Member]
Other income/(expense)
Equity in income of joint ventures, net	69,933	97,550
Other Real Estate Investments [Member]
Other income/(expense)
Equity in income of joint ventures, net	10,799	14,369
Revenues from rental properties	293,091	275,506
Management and other fee income	4,111	7,950
Total revenues	297,202	283,456
Rent	2,818	3,554
Real estate taxes	34,472	36,072
Operating and maintenance	34,553	33,902
General and administrative expenses	31,929	32,705
Provision for doubtful accounts	3,475	2,297
Impairment charges	5,840	6,473
Depreciation and amortization	84,856	74,569
Total operating expenses	197,943	189,490
Operating income	99,259	93,966
Mortgage financing income	410	1,136
Other expense, net	(580)	(768)
Interest expense	(52,451)	(52,578)
Income from continuing operations before income taxes, equity in income of joint ventures, gain on change in control of interests and equity in income of other real estate investments	46,638	41,756
Provision for income taxes, net	(12,112)	(12,717)
Equity in income of joint ventures, net	$ 69,933	97,550
Gain on change in control of interests, net		139,801
Income from continuing operations	$ 115,258	280,759
Discontinued operations
Loss from discontinued operating properties, net of tax		(15)
Impairment/loss on operating properties, net of tax		(60)
Loss from discontinued operations		(75)
Gain on sale of operating properties, net of tax	$ 26,896	32,055
Net income	142,154	312,739
Net income attributable to noncontrolling interests	(1,441)	(2,397)
Net income attributable to the Company	140,713	310,342
Preferred dividends	(11,555)	(14,573)
Net income available to the Company's common shareholders	$ 129,158	$ 295,769
-Basic (in dollars per share)	$ 0.31	$ 0.72
Income from continuing operations (in dollars per share)	0.31	0.71
Net income attributable to the Company:
-Basic (in dollars per share)	0.31	0.72
-Diluted (in dollars per share)	$ 0.31	$ 0.71
Weighted average shares:
-Basic (in shares)	412,630	410,433
-Diluted (in shares)	414,145	415,396
Income from continuing operations	$ 129,158	$ 295,844
Loss from discontinued operations attributable to the Company		(75)
Net income	$ 129,158	$ 295,769