Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Percentage of physical occupancy									95.00%
Anniversary of Completion of Development or Redevelopment (in years)									1 year
Reconciliation of NOI to net income
Net income	$ 242,183	$ 356,329	$ 197,319	$ 237,877	$ 155,352	$ 206,076	$ 172,253	$ 208,053	$ 1,033,708	$ 741,733	$ 697,327
Indirect operating expenses, net of corporate income									61,403	56,973	49,055
Investments and investment management expense									4,822	4,370	4,485
Expensed acquisition, development and other pursuit costs, net of recoveries									9,922	6,822	(3,717)
Interest expense, net									187,510	175,615	180,618
Gain (Loss) on Extinguishment of Debt									(7,075)	26,736	(412)
General and administrative expense									45,771	42,774	41,425
Equity in income of unconsolidated real estate entities									(64,962)	(70,018)	(148,766)
Depreciation expense									531,434	477,923	442,682
Income tax expense									305	1,483	9,368
Casualty and impairment (gain) loss, net									(3,935)	(10,542)	0
Gain on sale of real estate assets									(384,847)	(125,272)	(85,415)
Gain on sale of discontinued operations									0	0	(37,869)
Income from discontinued operations									0	0	(310)
Net operating income from real estate assets sold or held for sale, not classified as discontinued operations (2)									(17,509)	(34,133)	(49,708)
Net operating income									$ 1,410,697	$ 1,240,992	$ 1,099,587