Business Segments (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010	Dec. 31, 2009
Segment Reporting Entity Consolidated Revenue Details [Abstract]
Reconciling item	$ (11,352,000)	$ (827,000)	$ (23,940,000)	$ (6,687,000)
Total revenues	335,901,000	219,146,000	574,808,000	436,514,000
Reconciling items:
General and administrative expenses	(51,840,000)	(38,921,000)	(91,023,000)	(80,927,000)
Merger integration expenses and reduction in workforce	(103,052,000)	0	(109,040,000)	0
Depreciation and amortization expense	(123,079,000)	(76,871,000)	(205,744,000)	(152,012,000)
Earnings from other unconcolidated investees, net	46,000	2,477,000	1,099,000	4,590,000
Interest expense	(113,059,000)	(118,920,000)	(203,621,000)	(228,899,000)
Net gains on dispositions of investments in real estate	102,529,000	10,959,000	106,254,000	22,766,000
Foreign currency exchange gains, net	(10,255,000)	(7,206,000)	(8,881,000)	(3,518,000)
Loss on early extinguishment of debt, net	0	975,000	0	(46,658,000)
Loss before income taxes	(148,325,000)	(77,940,000)	(190,198,000)	(182,845,000)
Reconciling items:
Investments in and advances to other unconsolidated investees	93,335,000	6,987,000	93,335,000	6,987,000
Notes receivable backed by real estate	247,178,000	189,550,000	247,178,000	189,550,000
Assets held for sale	171,765,000	574,791,000	171,765,000	574,791,000	574,791,000
Cash and cash equivalents	260,893,000	37,634,000	260,893,000	37,634,000	37,634,000	34,362,000
Accounts receivable	60,879,000	68,388,000	60,879,000	68,388,000
Total reconciling items	834,050,000	877,350,000	834,050,000	877,350,000
Total assets	29,134,506,000	14,902,667,000	29,134,506,000	14,902,667,000
Americas | Direct owned
Segment Reporting Entity Consolidated Revenue Details [Abstract]
Total segment revenue	201,247,000	150,811,000	357,286,000	301,987,000
Net operating income:
Total segment net operating income	142,015,000	107,363,000	248,443,000	214,515,000
Assets:
Total segment assets	14,192,651,000	7,358,374,000	14,192,651,000	7,358,374,000
Americas | Private Capital
Segment Reporting Entity Consolidated Revenue Details [Abstract]
Total segment revenue	19,740,000	10,303,000	37,801,000	22,988,000
Net operating income:
Total segment net operating income	12,514,000	3,688,000	23,818,000	9,779,000
Assets:
Total segment assets	1,996,312,000	1,035,548,000	1,996,312,000	1,035,548,000
Europe
Assets:
Total segment assets	7,815,816,000	2,619,455,000	7,815,816,000	2,619,455,000
Europe | Direct owned
Segment Reporting Entity Consolidated Revenue Details [Abstract]
Total segment revenue	64,113,000	20,478,000	91,683,000	39,393,000
Net operating income:
Total segment net operating income	44,233,000	10,407,000	59,902,000	18,241,000
Europe | Private Capital
Segment Reporting Entity Consolidated Revenue Details [Abstract]
Total segment revenue	23,689,000	18,272,000	48,601,000	39,697,000
Net operating income:
Total segment net operating income	19,752,000	15,119,000	41,143,000	32,962,000
Assets:
Total segment assets	866,144,000	1,038,061,000	866,144,000	1,038,061,000
Asia | Direct owned
Segment Reporting Entity Consolidated Revenue Details [Abstract]
Total segment revenue	33,548,000	19,550,000	56,975,000	38,165,000
Net operating income:
Total segment net operating income	25,894,000	14,331,000	42,881,000	27,559,000
Assets:
Total segment assets	3,091,777,000	1,889,879,000	3,091,777,000	1,889,879,000
Asia | Private Capital
Segment Reporting Entity Consolidated Revenue Details [Abstract]
Total segment revenue	4,916,000	559,000	6,402,000	971,000
Net operating income:
Total segment net operating income	4,484,000	396,000	5,696,000	665,000
Assets:
Total segment assets	$ 337,756,000	$ 84,000,000	$ 337,756,000	$ 84,000,000