Segment Disclosures (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation from reported net income to NOI and adjusted NOI
Net income	$ 297,639	$ 236,858	$ 216,725	$ 233,784	$ 246,260	$ 199,043	$ 204,975	$ 196,564	$ 985,006	$ 846,842	$ 554,494
Interest income									(86,159)	(24,536)	(99,864)
Investment management fee income									(1,847)	(1,895)	(2,073)
Interest expense									435,252	416,172	415,455
Depreciation and amortization									423,312	353,704	346,055
General and administrative									109,233	79,395	96,059
Litigation provision											125,000
Impairments										7,878	15,400
Other income, net									(18,216)	(2,976)	(12,933)
Income taxes									5,815	(1,654)	1,301
Equity income from unconsolidated joint ventures									(64,433)	(54,455)	(46,750)
Total discontinued operations	(59,489)	(9,824)	(2,828)	(2,232)	(33,909)	(3,607)	(2,456)	(5,671)	(74,373)	(45,652)	(18,364)
NOI									1,713,590	1,572,823	1,373,780
Straight-line rents									(39,587)	(47,311)	(59,173)
DFL accretion									(86,055)	(94,240)	(74,007)
Amortization of above and below market lease intangibles, net									(6,646)	(2,232)	(4,510)
Lease termination fees									(217)	(636)	(5,873)
NOI adjustments related to discontinued operations									(47)	1,585	2,329
Adjusted (Cash) NOI									$ 1,581,038	$ 1,429,989	$ 1,232,546