Segment Reporting (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Reconciliation of NOI to net income
Net income		$ 206,076	$ 241,001	$ 586,381	$ 554,801
Indirect operating expenses, net of corporate income		13,427	13,173	43,642	36,333
Investments and investment management expense		1,167	1,079	3,274	3,195
Expensed acquisition, development and other pursuit costs		3,391	406	5,251	3,139
Interest expense, net	[1]	43,234	46,376	133,398	132,631
(Gain) loss on extinguishment of debt, net		(18,987)	0	(26,736)	412
General and administrative expense		10,503	11,290	32,614	30,745
Equity in (income) loss of unconsolidated real estate entities		(20,554)	(130,592)	(68,925)	(143,527)
Depreciation expense	[1]	120,184	111,836	355,664	328,598
Casualty and Impairment Loss (Gain)		658	0	(10,668)	0
Gain on sale of real estate assets		(35,216)	0	(115,798)	(60,945)
Gain on sale of discontinued operations		0	0	0	(37,869)
Income from discontinued operations		0	0	0	(310)
Net operating income from real estate assets sold or held for sale, not classified as discontinued operations		(843)	(4,144)	(3,634)	(16,666)
Net operating income		323,040	290,425	934,463	830,537
Continuing Operations
Reconciliation of NOI to net income
Net operating income		$ 323,040	$ 290,425	$ 934,463	$ 830,537

[1] Includes amounts associated with assets sold or held for sale, not classified as discontinued operations.