Segment Reporting (Details) (USD $)	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014	Dec. 31, 2014
Summary of information for reportable segments
Rental income	$ 379,587,000		$ 336,455,000
Resident fees and services	492,510,000		456,265,000
Interest income	16,994,000		8,594,000
Other income	5,086,000		493,000
Total revenues	894,177,000		801,807,000
Property operating expenses	376,461,000		341,431,000
Net Operating Income from Continuing Operations	517,716,000	[1]	460,376,000
Interest expense	121,080,000		120,833,000
Loss (gain) on derivatives, net	(58,427,000)	[2]
Depreciation and amortization	188,829,000		233,318,000
General and administrative	35,138,000		32,865,000
Transaction costs	48,554,000		952,000
Loss (gain) on extinguishment of debt, net	(15,401,000)		148,000
Provision for loan losses	0
Impairment of Asset	2,220,000
Income (loss) from continuing operations before income taxes and income from unconsolidated entities	164,921,000		72,556,000
Income tax (expense) benefit	304,000		(2,260,000)
(Loss) income from unconsolidated entities	(12,648,000)		(5,556,000)
Income (loss) from continuing operations	152,577,000		64,740,000
Discontinued Operation, Amount of Other Income (Loss) from Disposition of Discontinued Operation, Net of Tax			460,000
Gain (loss) on real estate dispositions, net	56,845,000
Net income	209,422,000		65,200,000
Total assets	26,629,395,000			25,014,296,000
Percent Of Assets	1			1
Percent Of Revenues	1		1
Triple Net [Member]
Summary of information for reportable segments
Rental income	264,406,000		237,716,000
Resident fees and services	0		0
Interest income	14,699,000		7,720,000
Other income	3,883,000		144,000
Total revenues	282,988,000		245,580,000
Property operating expenses			243,000
Net Operating Income from Continuing Operations	282,988,000		245,337,000
Interest expense	10,027,000		9,115,000
Loss (gain) on derivatives, net	(58,427,000)		0
Depreciation and amortization	70,031,000		67,269,000
General and administrative	0		0
Transaction costs	36,172,000		275,000
Loss (gain) on extinguishment of debt, net	10,336,000		0
Provision for loan losses			0
Impairment of Asset	2,220,000
Income (loss) from continuing operations before income taxes and income from unconsolidated entities	212,629,000		168,678,000
Income tax (expense) benefit	418,000		(355,000)
(Loss) income from unconsolidated entities	1,393,000		1,382,000
Income (loss) from continuing operations	214,440,000		169,705,000
Discontinued Operation, Amount of Other Income (Loss) from Disposition of Discontinued Operation, Net of Tax			460,000
Gain (loss) on real estate dispositions, net	54,097,000
Net income	268,537,000		170,165,000
Total assets	11,916,636,000
Senior housing - operating [Member]
Summary of information for reportable segments
Rental income	0		0
Resident fees and services	492,510,000		456,265,000
Interest income	1,031,000		0
Other income	1,020,000		54,000
Total revenues	494,561,000		456,319,000
Property operating expenses	338,507,000		308,184,000
Net Operating Income from Continuing Operations	156,054,000		148,135,000
Interest expense	34,458,000		27,479,000
Loss (gain) on derivatives, net	0		0
Depreciation and amortization	76,636,000		129,162,000
General and administrative	0		0
Transaction costs	12,042,000		630,000
Loss (gain) on extinguishment of debt, net	0		(148,000)
Other expenses	0
Income (loss) from continuing operations before income taxes and income from unconsolidated entities	32,918,000		(8,988,000)
Income tax (expense) benefit	(533,000)		(1,643,000)
(Loss) income from unconsolidated entities	(15,073,000)		(7,961,000)
Income (loss) from continuing operations	17,312,000		(18,592,000)
Net income	17,312,000		(18,592,000)
Total assets	10,208,763,000
Outpatient Medical [Member]
Summary of information for reportable segments
Rental income	115,181,000		98,739,000
Resident fees and services	0		0
Interest income	1,264,000		874,000
Other income	161,000		280,000
Total revenues	116,606,000		99,893,000
Property operating expenses	37,954,000		33,004,000
Net Operating Income from Continuing Operations	78,652,000		66,889,000
Interest expense	7,625,000		9,383,000
Loss (gain) on derivatives, net	0		0
Depreciation and amortization	42,162,000		36,887,000
General and administrative	0		0
Transaction costs	341,000		47,000
Loss (gain) on extinguishment of debt, net	0
Income (loss) from continuing operations before income taxes and income from unconsolidated entities	28,524,000		20,572,000
Income tax (expense) benefit	466,000		(262,000)
(Loss) income from unconsolidated entities	1,032,000		1,023,000
Income (loss) from continuing operations	30,022,000		21,333,000
Gain (loss) on real estate dispositions, net	2,749,000
Net income	32,771,000		21,333,000
Total assets	4,444,058,000
Non Segment Corporate [Member]
Summary of information for reportable segments
Rental income	0		0
Resident fees and services	0		0
Interest income	0		0
Other income	22,000		15,000
Total revenues	22,000		15,000
Property operating expenses	0		0
Net Operating Income from Continuing Operations	22,000		15,000
Interest expense	68,970,000		74,856,000
Loss (gain) on derivatives, net	0		0
Depreciation and amortization	0		0
General and administrative	35,138,000		32,865,000
Transaction costs	0		0
Loss (gain) on extinguishment of debt, net	5,064,000		0
Income (loss) from continuing operations before income taxes and income from unconsolidated entities	(109,150,000)		(107,706,000)
Income tax (expense) benefit	(48,000)		0
(Loss) income from unconsolidated entities	0		0
Income (loss) from continuing operations	(109,198,000)		(107,706,000)
Net income	(109,198,000)		(107,706,000)
Total assets	59,938,000
International [Member]
Summary of information for reportable segments
Total revenues	149,041,000		126,708,000
Total assets	4,748,464,000			4,285,819,000
Percent Of Assets	0.178			0.171
Percent Of Revenues	0.167		0.158
United States [Member]
Summary of information for reportable segments
Total revenues	745,136,000		675,099,000
Total assets	$ 21,880,931,000			$ 20,728,477,000
Percent Of Assets	0.822			0.829
Percent Of Revenues	0.833		0.842

[1] (1)     Genesis Healthcare is in our triple-net segment. Sunrise Senior Living and Revera are in our seniors housing operating segment. Brookdale Senior Living and Benchmark Senior Living are in both our triple-net and seniors housing operating segments.

[2] (1) In April 2011, we completed the acquisition of substantially all of the real estate assets of privately-owned Genesis Healthcare Corporation. In conjunction with this transaction, we received the option to acquire an ownership interest in Genesis Healthcare. In February 2015, Genesis Healthcare closed on a transaction to merge with Skilled Healthcare Group to become a publicly traded company which required us to record the value of the derivative asset due to the net settlement feature.