Segment Reporting (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Summary of information for reportable segments
Rental income	$ 311,731,000	$ 277,919,000	$ 909,659,000	$ 789,748,000
Resident fees and services	466,127,000	174,464,000	1,164,446,000	498,295,000
Interest income	7,629,000	8,111,000	24,325,000	24,131,000
Other income	1,443,000	1,339,000	3,168,000	4,505,000
Revenues	786,930,000	461,833,000	2,101,598,000	1,316,679,000
Property operating expenses	342,730,000	144,417,000	874,960,000	409,236,000
Net Operating Income from Continuing Operations	444,200,000	317,416,000	1,226,638,000	907,443,000
Interest expense	116,530,000	91,915,000	336,585,000	271,223,000
Loss (gain) on derivatives, net	4,872,000	409,000	4,465,000	(1,712,000)
Depreciation and amortization	242,668,000	127,844,000	628,700,000	373,344,000
General and administrative	28,718,000	23,679,000	79,799,000	77,302,000
Transaction costs	23,591,000	8,264,000	117,707,000	42,535,000
Loss (gain) on extinguishment of debt, net	4,068,000	(215,000)	4,376,000	(791,000)
Provision for loan losses	0	27,008,000	0	27,008,000
Income (loss) from continuing operations before income taxes and income from unconsolidated entities	31,889,000	38,082,000	63,758,000	116,952,000
Total assets	23,049,805,000		23,049,805,000		19,549,109,000
Percent Of Assets	1		1		1
Percent Of Revenues	1	1	1	1
Senior housing - triple net [Member]
Summary of information for reportable segments
Rental income	199,408,000	178,193,000	573,112,000	508,004,000
Resident fees and services	0	0	0	0
Interest income	5,035,000	6,116,000	16,311,000	17,977,000
Other income	778,000	662,000	1,183,000	2,268,000
Revenues	205,221,000	184,971,000	590,606,000	528,249,000
Property operating expenses	0	0	0	0
Net Operating Income from Continuing Operations	205,221,000	184,971,000	590,606,000	528,249,000
Interest expense	(5,968,000)	(347,000)	(15,841,000)	(602,000)
Loss (gain) on derivatives, net	(4,872,000)	0	(4,872,000)	(96,000)
Depreciation and amortization	(58,148,000)	(52,294,000)	(169,603,000)	(147,074,000)
General and administrative	0	0	0	0
Transaction costs	(4,026,000)	(5,590,000)	(15,730,000)	(30,796,000)
Loss (gain) on extinguishment of debt, net	0	(126,000)	0	(2,363,000)
Provision for loan losses	0	(27,008,000)	0	(27,008,000)
Income (loss) from continuing operations before income taxes and income from unconsolidated entities	132,207,000	99,606,000	384,560,000	320,310,000
Total assets	9,222,731,000		9,222,731,000
Senior housing - operating [Member]
Summary of information for reportable segments
Rental income	0	0	0	0
Resident fees and services	466,127,000	174,464,000	1,164,446,000	498,295,000
Interest income	0	0	757,000	0
Other income	167,000	0	169,000	0
Revenues	466,294,000	174,464,000	1,165,372,000	498,295,000
Property operating expenses	(311,575,000)	(118,369,000)	(785,050,000)	(336,952,000)
Net Operating Income from Continuing Operations	154,719,000	56,095,000	380,322,000	161,343,000
Interest expense	(24,693,000)	(17,474,000)	(63,175,000)	(49,537,000)
Loss (gain) on derivatives, net	0	(409,000)	407,000	1,808,000
Depreciation and amortization	(144,578,000)	(39,591,000)	(338,099,000)	(123,820,000)
General and administrative	0	0	0	0
Transaction costs	(18,882,000)	(1,966,000)	(101,006,000)	(6,365,000)
Loss (gain) on extinguishment of debt, net	5,252,000	(89,000)	5,560,000	1,089,000
Provision for loan losses	0	0	0	0
Income (loss) from continuing operations before income taxes and income from unconsolidated entities	(28,182,000)	(3,434,000)	(115,991,000)	(15,482,000)
Total assets	9,031,224,000		9,031,224,000
Medical facilities [Member]
Summary of information for reportable segments
Rental income	112,323,000	99,726,000	336,547,000	281,744,000
Resident fees and services	0	0	0	0
Interest income	2,594,000	1,995,000	7,257,000	6,154,000
Other income	466,000	400,000	1,539,000	1,482,000
Revenues	115,383,000	102,121,000	345,343,000	289,380,000
Property operating expenses	(31,155,000)	(26,048,000)	(89,910,000)	(72,284,000)
Net Operating Income from Continuing Operations	84,228,000	76,073,000	255,433,000	217,096,000
Interest expense	(9,143,000)	(7,940,000)	(28,441,000)	(22,338,000)
Loss (gain) on derivatives, net	0	0	0	0
Depreciation and amortization	(39,942,000)	(35,959,000)	(120,998,000)	(102,450,000)
General and administrative	0	0	0	0
Transaction costs	(683,000)	(708,000)	(971,000)	(5,374,000)
Loss (gain) on extinguishment of debt, net	0	0	0	483,000
Provision for loan losses	0	0	0	0
Income (loss) from continuing operations before income taxes and income from unconsolidated entities	34,460,000	31,466,000	105,023,000	87,417,000
Total assets	4,645,540,000		4,645,540,000
Non Segment Corporate [Member]
Summary of information for reportable segments
Rental income	0	0	0	0
Resident fees and services	0	0	0	0
Interest income	0	0	0	0
Other income	32,000	277,000	277,000	755,000
Revenues	32,000	277,000	277,000	755,000
Property operating expenses	0	0	0	0
Net Operating Income from Continuing Operations	32,000	277,000	277,000	755,000
Interest expense	(76,726,000)	(66,154,000)	(229,128,000)	(198,746,000)
Loss (gain) on derivatives, net	0	0	0	0
Depreciation and amortization	0	0	0	0
General and administrative	(28,718,000)	(23,679,000)	(79,799,000)	(77,302,000)
Transaction costs	0	0	0	0
Loss (gain) on extinguishment of debt, net	(1,184,000)	0	(1,184,000)	0
Provision for loan losses	0	0	0	0
Income (loss) from continuing operations before income taxes and income from unconsolidated entities	(106,596,000)	(89,556,000)	(309,834,000)	(275,293,000)
Total assets	150,310,000		150,310,000
International [Member]
Summary of information for reportable segments
Revenues	116,962,000	7,091,000	264,530,000	9,146,000
Total assets	3,427,229,000		3,427,229,000		856,895,000
Percent Of Assets	0.149		0.149		0.044
Percent Of Revenues	0.149	0.015	0.126	0.007
United States [Member]
Summary of information for reportable segments
Revenues	669,968,000	454,742,000	1,837,068,000	1,307,533,000
Total assets	$ 19,622,576,000		$ 19,622,576,000		$ 18,692,214,000
Percent Of Assets	0.851		0.851		0.956
Percent Of Revenues	0.851	0.985	0.874	0.993