Segment Reporting (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
Segment Reporting Information Profit Loss
Revenues	$ 168,058	$ 70,377	$ 67,182	$ 68,378	$ 60,971	$ 75,913	$ 115,735	$ 75,165	$ 373,995	$ 327,784	$ 260,645
Operating expenses	(123,615)	(85,889)	(59,005)	(56,693)	(50,218)	(51,626)	(52,283)	(48,346)	(325,202)	(202,473)	(169,029)
Interest expense									(50,573)	(21,770)	(15,636)
Other, net									87,287	85,607	32,690
Provision for income taxes									(6,783)	(37,214)	(25,814)
Income from continuing operations, net of tax									78,724	151,934	82,856
Segment Reporting Asset Balances
Assets	4,609,042				1,462,623				4,609,042	1,462,623
Long-Lived Assets	4,306,251				1,343,890				4,306,251	1,343,890
Real Estate Ownership
Segment Reporting Information Profit Loss
Revenues									150,815	85,137	68,755
Operating expenses									(118,152)	(44,901)	(35,346)
Interest expense									(50,573)	(21,770)	(15,636)
Other, net									83,409	82,912	30,131
Provision for income taxes									(4,012)	(2,243)	(2,154)
Income from continuing operations, net of tax									61,487	99,135	45,750
Segment Reporting Asset Balances
Assets	4,484,821				1,334,066				4,484,821	1,334,066	1,048,405
Long-Lived Assets	4,236,993				1,273,521				4,236,993	1,273,521	1,034,745
Foreign Properties | Real Estate Ownership
Segment Reporting Information Profit Loss
Revenues									30,113	9,729	7,706
Operating expenses									(2,520)	(4,859)	(3,742)
Interest expense									(11,531)	(1,695)	(1,742)
Other, net									6,606	6,176	3,943
Provision for income taxes									(1,315)	(108)	(30)
Income from continuing operations, net of tax									21,353	9,243	6,135
Segment Reporting Asset Balances
Assets	956,903				75,522				956,903	75,522	82,987
Long-Lived Assets	875,796				70,047				875,796	70,047	73,447
Domestic properties | Real Estate Ownership
Segment Reporting Information Profit Loss
Revenues									120,702	75,408	61,049
Operating expenses									(115,632)	(40,042)	(31,604)
Interest expense									(39,042)	(20,075)	(13,894)
Other, net									76,803	76,736	26,188
Provision for income taxes									(2,697)	(2,135)	(2,124)
Income from continuing operations, net of tax									40,134	89,892	39,615
Segment Reporting Asset Balances
Assets	3,527,918				1,258,544				3,527,918	1,258,544	965,418
Long-Lived Assets	$ 3,361,197				$ 1,203,474				$ 3,361,197	$ 1,203,474	$ 961,298