Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues
Revenues from rental properties, net		$ 1,044,888	$ 1,142,334	$ 1,149,603
Management and other fee income		13,005	16,550	15,159
Total revenues		1,057,893	1,158,884	1,164,762
Operating expenses
Rent		(11,270)	(11,311)	(10,929)
Real estate taxes		(157,661)	(153,659)	(153,336)
Operating and maintenance		(174,038)	(171,981)	(164,294)
General and administrative		(93,217)	(96,942)	(87,797)
Provision for doubtful accounts		0	0	(6,253)
Impairment charges		6,624	48,743	79,207
Depreciation and amortization		(288,955)	(277,879)	(310,380)
Total operating expenses		(731,765)	(760,515)	(812,196)
Gain on sale of properties/change in control of interests		6,484	79,218	229,840
Operating income		332,612	477,587	582,406
Other income/(expense)
Other income, net		4,119	10,985	16,528
Gain/(loss) on marketable securities, net		594,753	829	(3,487)
Gain on sale of cost method investment		190,832	0	0
Interest expense		(186,904)	(177,395)	(183,339)
Early extinguishment of debt charges		(7,538)	0	(12,762)
Income before income taxes, net, equity in income of joint ventures, net, and equity in income from other real estate investments, net		927,874	312,006	399,346
(Provision)/benefit for income taxes, net		(978)	3,317	(1,600)
Net income		1,002,877	413,561	498,463
Net income attributable to noncontrolling interests		(2,044)	(2,956)	(668)
Net income attributable to the Company		1,000,833	410,605	497,795
Preferred stock redemption charges		0	(18,528)	0
Preferred dividends		(25,416)	(52,089)	(58,191)
Net income available to the Company's common shareholders		$ 975,417	$ 339,988	$ 439,604
Per common share:
-Basic (in dollars per share)		$ 2.26	$ 0.80	$ 1.02
-Diluted (in dollars per share)		$ 2.25	$ 0.80	$ 1.02
Weighted average shares:
-Basic (in shares)		429,950	420,370	420,641
-Diluted (in shares)	[1]	431,633	421,799	421,379
Joint Ventures [Member]
Other income/(expense)
Equity in income		$ 47,353	$ 72,162	$ 71,617
Other Real Estate Investments [Member]
Other income/(expense)
Equity in income		$ 28,628	$ 26,076	$ 29,100

[1] The effect of the assumed conversion of certain convertible units had an anti-dilutive effect upon the calculation of Income from continuing operations per share. Accordingly, the impact of such conversions has not been included in the determination of diluted earnings per share calculations. Additionally, there were 1.2 million, 0.5 million and 1.3 million stock options that were not dilutive as of December 31, 2020, 2019 and 2018, respectively.