Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Continuing Operations [Member]
Operating expenses
Impairment charges	$ 10,073	$ 6,058	$ 68,126	$ 27,908
Joint Ventures [Member]
Other income/(expense)
Equity in income of joint ventures, net	11,537	10,894	190,155	130,808
Other Real Estate Investments [Member]
Operating expenses
Impairment charges				5,300
Other income/(expense)
Equity in income of joint ventures, net	3,774	11,319	22,532	31,236
Revenues from rental properties	279,286	283,387	859,492	847,973
Management and other fee income	5,790	4,995	14,274	17,926
Total revenues	285,076	288,382	873,766	865,899
Rent	2,728	2,913	8,274	9,479
Real estate taxes	37,703	36,571	107,966	109,343
Operating and maintenance	32,590	34,915	100,366	104,926
General and administrative expenses	27,983	27,310	89,840	89,322
Provision for doubtful accounts	1,092	1,920	5,752	5,324
Impairment charges			68,126	27,989
Depreciation and amortization	96,827	103,708	264,436	258,432
Total operating expenses	208,996	213,395	644,760	604,734
Operating income	76,080	74,987	229,006	261,165
Mortgage financing income	408	445	1,232	2,497
Interest, dividends and other investment income	477	5,692	827	38,011
Other income, net	3,473	615	1,117	100
Interest expense	(46,552)	(54,031)	(149,482)	(162,739)
Early extinguishment of debt charges	(45,674)		(45,674)
Income/(loss) 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	(11,788)	27,708	37,026	139,034
Provision for income taxes, net	(61,426)	(2,844)	(73,292)	(11,933)
Equity in income of joint ventures, net	11,500	10,900	190,155	130,808
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain	6,584	6,342	53,096	146,143
Income/(loss) from continuing operations	(51,319)	53,419	229,517	435,288
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	9,771	27,665	75,935	86,219
Net income/(loss)	(41,548)	81,084	305,452	521,432
Net income attributable to noncontrolling interests	(1,997)	(3,512)	(4,875)	(6,518)
Net income/(loss) attributable to the Company	(43,545)	77,572	300,577	514,914
Preferred dividends	(11,555)	(14,573)	(34,665)	(43,719)
Net income/(loss) available to the Company's common shareholders	$ (55,100)	$ 62,999	$ 265,912	$ 471,195
-Basic (in dollars per share)	$ (0.13)	$ 0.15	$ 0.63	$ 1.14
-Diluted (in dollars per share)	(0.13)	0.15	0.63	1.14
Net income/(loss) attributable to the Company:
-Basic (in dollars per share)	(0.13)	0.15	0.63	1.14
-Diluted (in dollars per share)	$ (0.13)	$ 0.15	$ 0.63	$ 1.14
Weighted average shares:
-Basic (in shares)	420,073	411,487	416,829	411,202
-Diluted (in shares)	420,073	412,686	418,234	413,262
Income/(loss) from continuing operations	$ (55,100)	$ 62,999	$ 265,912	$ 471,270
Loss from discontinued operations				(75)
Net income/(loss)	$ (55,100)	$ 62,999	$ 265,912	$ 471,195