Segment Disclosures (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reconciliation from reported net income to NOI and adjusted NOI
Net income	$ 246,260	$ 199,043	$ 204,975	$ 196,564	$ 70,787	$ 175,471	$ 234,252	$ 73,984	$ 846,842	$ 554,494	$ 344,395
Interest income									(24,536)	(99,864)	(160,163)
Investment management fee income									(1,895)	(2,073)	(4,666)
Interest expense									417,130	416,396	285,508
Depreciation and amortization									358,245	349,922	306,934
General and administrative									79,454	96,121	83,019
Litigation settlement and provision										125,000
Impairments (recoveries)									7,878	15,400	(11,900)
Other income, net									(2,776)	(12,732)	(16,194)
Income taxes									(1,636)	1,250	412
Equity income from unconsolidated joint ventures									(54,455)	(46,750)	(4,770)
Impairments of investments in unconsolidated joint ventures											71,693
Total discontinued operations	(31,031)	(1,153)	597	(2,371)	(2,920)	(962)	(1,653)	(1,621)	(33,958)	(7,156)	(29,049)
NOI									1,590,293	1,390,008	865,219
Straight-line rents									(47,311)	(59,173)	(47,243)
DFL accretion									(94,240)	(74,007)	(10,641)
Amortization of above and below market lease intangibles, net									(2,232)	(4,510)	(6,378)
Lease termination fees									(636)	(5,873)	(7,665)
NOI adjustments related to discontinued operations									1,486	2,061	2,309
Adjusted NOI									$ 1,447,360	$ 1,248,506	$ 795,601