Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Reconciliation of NOI to net income
Net income	$ 197,319	$ 172,253	$ 435,197	$ 380,306
Indirect operating expenses, net of corporate income	15,477	14,817	32,015	30,215
Investments and investment management expense	1,194	1,073	2,340	2,107
Expensed acquisition, development and other pursuit costs, net of recoveries	1,436	673	4,897	1,860
Interest expense, net	46,581	44,590	89,991	90,164
Loss (gain) on extinguishment of debt, net	2,461	(7,749)	2,461	(7,749)
General and administrative expense	12,011	10,335	23,414	20,803
Equity in (income) loss of unconsolidated real estate entities	(27,151)	(13,806)	(55,120)	(48,371)
Depreciation expense	132,469	118,627	259,685	235,480
Income tax expense	36	1,293	73	1,308
Casualty and Impairment Loss (Gain)	(1,732)	(17,114)	(3,935)	(11,326)
Gain on sale of real estate assets in continuing operations	(31,133)	(9,625)	(82,563)	(80,583)
Net operating income from real estate assets sold or held for sale (1)	(1,192)	(4,377)	(3,218)	(8,812)
Net operating income	$ 347,776	$ 310,990	$ 705,237	$ 605,402