Segment Reporting (Details) (USD $)	5 Months Ended	12 Months Ended
	May 22, 2013	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Summary of information for reportable segments
Rental income		$ 1,227,589,000		$ 1,063,214,000		$ 804,732,000
Resident fees and services		1,616,290,000		697,494,000		456,085,000
Interest income		32,663,000		39,065,000		41,070,000
Other income		4,066,000		5,271,000		11,295,000
Total revenues		2,880,608,000		1,805,044,000		1,313,182,000
Property operating expenses		1,206,813,000		567,989,000		375,064,000
Net operating income from continuing operations		1,673,795,000		1,237,055,000		938,118,000
Interest expense		458,360,000		361,565,000		290,981,000
Loss (gain) on derivatives, net	10,355,000	(4,470,000)		1,825,000		0
Depreciation and amortization		865,800,000		506,220,000		386,478,000
General and administrative		108,318,000		97,341,000		77,201,000
Transaction costs		133,401,000		61,609,000		70,224,000
Loss (gain) on extinguishment of debt, net		909,000		775,000		979,000
Provision for loan losses		2,110,000	[1]	27,008,000	[2]	2,010,000	[3]
Income from continuing operations before income taxes and income from unconsolidated entities		102,245,000		185,912,000		112,203,000
Total assets		23,083,957,000		19,549,109,000
Segment Reporting (Textuals)
Percent of Assets		1		1
Percent of Revenues		1		1		1
Senior Housing Facilities Operating [Member]
Summary of information for reportable segments
Rental income		0		0		0
Resident fees and services		1,616,290,000		697,494,000		456,085,000
Interest income		757,000		6,208,000		0
Other income		355,000		0		0
Total revenues		1,617,402,000		703,702,000		456,085,000
Property operating expenses		1,089,239,000		471,678,000		314,142,000
Net operating income from continuing operations		528,163,000		232,024,000		141,943,000
Interest expense		92,148,000		67,524,000		46,342,000
Loss (gain) on derivatives, net		407,000		1,921,000
Depreciation and amortization		478,007,000		165,798,000		138,192,000
General and administrative		0		0		0
Transaction costs		107,066,000		12,756,000		36,328,000
Loss (gain) on extinguishment of debt, net		(3,372,000)		(2,697,000)		979,000
Provision for loan losses		0		0		0
Income from continuing operations before income taxes and income from unconsolidated entities		(145,279,000)		(9,436,000)		(77,940,000)
Total assets		8,984,316,000		5,323,777,000
Senior Housing Facilities Triple Net [Member]
Summary of information for reportable segments
Rental income		780,785,000		684,097,000		537,581,000
Resident fees and services		0		0		0
Interest income		21,512,000		24,380,000		34,068,000
Other income		1,434,000		2,412,000		6,620,000
Total revenues		803,731,000		710,889,000		578,269,000
Property operating expenses		0		0		0
Net operating income from continuing operations		803,731,000		710,889,000		578,269,000
Interest expense		23,322,000		1,745,000		(2,802,000)
Loss (gain) on derivatives, net		(4,877,000)		(96,000)
Depreciation and amortization		228,523,000		200,899,000		155,797,000
General and administrative		0		0		0
Transaction costs		24,350,000		35,705,000		27,993,000
Loss (gain) on extinguishment of debt, net		40,000		2,405,000		0
Provision for loan losses		2,110,000		27,008,000		0
Income from continuing operations before income taxes and income from unconsolidated entities		520,509,000		443,031,000		397,281,000
Total assets		9,232,833,000		8,447,698,000
Medical Facilities [Member]
Summary of information for reportable segments
Rental income		446,804,000		379,117,000		267,151,000
Resident fees and services		0		0		0
Interest income		10,394,000		8,477,000		7,002,000
Other income		1,981,000		1,947,000		3,985,000
Total revenues		459,179,000		389,541,000		278,138,000
Property operating expenses		117,574,000		96,311,000		60,922,000
Net operating income from continuing operations		341,605,000		293,230,000		217,216,000
Interest expense		36,823,000		28,878,000		18,557,000
Loss (gain) on derivatives, net		0		0
Depreciation and amortization		159,270,000		139,523,000		92,489,000
General and administrative		0		0		0
Transaction costs		1,985,000		13,148,000		5,903,000
Loss (gain) on extinguishment of debt, net		0		(483,000)		0
Provision for loan losses		0		0		2,010,000
Income from continuing operations before income taxes and income from unconsolidated entities		143,527,000		112,164,000		98,257,000
Total assets		4,718,527,000		4,706,159,000
Non Segment Corporate [Member]
Summary of information for reportable segments
Rental income		0		0		0
Resident fees and services		0		0		0
Interest income		0		0		0
Other income		296,000		912,000		690,000
Total revenues		296,000		912,000		690,000
Property operating expenses		0		0		0
Net operating income from continuing operations		296,000		912,000		690,000
Interest expense		306,067,000		263,418,000		228,884,000
Loss (gain) on derivatives, net		0		0
Depreciation and amortization		0		0		0
General and administrative		108,318,000		97,341,000		77,201,000
Transaction costs		0		0		0
Loss (gain) on extinguishment of debt, net		2,423,000		0		0
Provision for loan losses		0		0		0
Income from continuing operations before income taxes and income from unconsolidated entities		(416,512,000)		(359,847,000)		(305,395,000)
Total assets		148,281,000		1,071,475,000
International [Member]
Summary of information for reportable segments
Total revenues		391,412,000		26,537,000		0
Total assets		3,324,012,000		856,895,000
Segment Reporting (Textuals)
Percent of Assets		0.144		0.044
Percent of Revenues		0.136		0.015		0
United States [Member]
Summary of information for reportable segments
Total revenues		2,489,196,000		1,778,507,000		1,313,182,000
Total assets		$ 19,759,945,000		$ 18,692,214,000
Segment Reporting (Textuals)
Percent of Assets		0.856		0.956
Percent of Revenues		0.864		0.985		1

[1] Provision and charge-off amounts relate to one active adult community in our seniors housing triple-net segment.

[2] Provision and charge-off amounts relate to one entrance fee community in our seniors housing triple-net segment.

[3] Provision and charge-off amounts relate to one hospital in our medical facilities segment.