Segment Disclosures (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Reconciliation from reported net income to NOI and adjusted NOI
Net income	$ 233,784	$ 196,564
Interest income	(12,386)	(819)
Investment management fee income	(443)	(493)
Interest expense	109,351	103,752
Depreciation and amortization	104,717	85,280
General and administrative	20,744	20,089
Other income, net	(12,012)	(436)
Income taxes	881	(709)
Equity income from unconsolidated joint ventures	(14,801)	(13,675)
Total discontinued operations		(2,371)
NOI	429,835	387,182
Straight-line rents	(18,793)	(9,927)
DFL accretion	(24,170)	(25,622)
Amortization of above and below market lease intangibles, net	(78)	(697)
Lease termination fees		(148)
NOI adjustments related to discontinued operations		626
Adjusted NOI	$ 386,794	$ 351,414