Segment Disclosures (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Reconciliation from reported net income to NOI and Adjusted NOI
Net income	$ 204,975	$ 234,252	$ 401,539	$ 308,236
Interest income	(1,216)	(60,526)	(2,035)	(98,622)
Investment management fee income	(470)	(504)	(963)	(1,111)
Interest expense	103,225	105,129	207,793	213,705
Depreciation and amortization	87,924	89,814	176,165	180,996
General and administrative	14,812	34,872	34,914	56,824
Other income, net	(1,028)	(7,518)	(1,464)	(17,827)
Income taxes	176	248	(533)	285
Equity income from unconsolidated joint ventures	(15,732)	(14,950)	(29,407)	(15,748)
Total discontinued operations, net of income taxes		(337)	(2,993)	(678)
NOI	392,666	380,480	783,016	626,060
Straight-line rents	(11,860)	(15,612)	(21,787)	(32,912)
DFL accretion	(22,017)	(22,262)	(47,639)	(24,937)
Amortization of above and below market lease intangibles, net	(625)	(1,187)	(1,322)	(2,093)
Lease termination fees	(251)	(1,589)	(399)	(3,178)
NOI adjustments related to discontinued operations			148
Adjusted NOI	$ 357,913	$ 339,830	$ 712,017	$ 562,940