Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Reconciliation of NOI to net income
Net income	$ 235,781	$ 237,877
Indirect operating expenses, net of corporate income	16,297	16,537
Investments and investment management expense	1,321	1,145
Expensed acquisition, development and other pursuit costs, net of recoveries	728	3,462
Interest expense, net	49,295	43,410
General and administrative expense	13,206	11,404
Equity in income of unconsolidated real estate entities	(16,672)	(27,969)
Depreciation expense	140,621	127,216
Income tax expense	20	37
Casualty and impairment loss (gain), net	11,688	(2,202)
Gain on sale of real estate	(88,315)	(51,430)
Net operating income from real estate assets sold or held for sale	(1,387)	(8,606)
Net operating income	$ 362,583	$ 350,881