Segment Reporting (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($)		Mar. 31, 2015 USD ($)		Dec. 31, 2015 USD ($)
Summary of information for reportable segments
Rental income	$ 415,663		$ 379,587
Resident fees and services	602,149		492,510
Interest income	25,188		16,994
Other income	4,050		5,086
Total revenues	1,047,050		894,177
Property operating expenses	449,636		376,461
Net Operating Income from Continuing Operations	597,414	[1]	517,716
Interest expense	132,960		121,080
Loss (gain) on derivatives, net	0		(58,427)	[2]
Depreciation and amortization	228,696		188,829
General and administrative	45,691		35,138
Transaction costs	8,208		48,554
Loss (gain) on extinguishment of debt, net	(24)		15,401
Impairment of Asset	14,314		2,220
Income (loss) from continuing operations before income taxes and income from unconsolidated entities	167,569		164,921
Income tax (expense) benefit	1,725		304
(Loss) income from unconsolidated entities	(3,820)		(12,648)
Income (loss) from continuing operations	165,474		152,577
Gain (loss) on real estate dispositions, net	0		56,845
Net income	165,474		$ 209,422
Total assets	$ 29,088,293				$ 29,023,845
Percent Of Assets	1				1
Percent Of Revenues	1		1
Triple Net [Member]
Summary of information for reportable segments
Rental income	$ 283,825		$ 261,993
Resident fees and services	0		0
Interest income	22,853		14,699
Other income	1,490		3,883
Total revenues	308,168		280,575
Property operating expenses	0		0
Net Operating Income from Continuing Operations	308,168		280,575
Interest expense	5,606		8,424
Loss (gain) on derivatives, net	0		(58,427)
Depreciation and amortization	79,800		69,420
General and administrative	0		0
Transaction costs	2,852		36,171
Loss (gain) on extinguishment of debt, net	(24)		10,337
Impairment of Asset	14,314		2,220
Income (loss) from continuing operations before income taxes and income from unconsolidated entities	205,620		212,430
Income tax (expense) benefit	(317)		419
(Loss) income from unconsolidated entities	3,081		1,393
Income (loss) from continuing operations	208,384		214,242
Gain (loss) on real estate dispositions, net	0		54,096
Net income	208,384		268,338
Total assets	12,337,195
Senior housing - operating [Member]
Summary of information for reportable segments
Rental income	0		0
Resident fees and services	602,149		492,510
Interest income	1,031		1,031
Other income	2,189		1,020
Total revenues	605,369		494,561
Property operating expenses	408,894		338,507
Net Operating Income from Continuing Operations	196,475		156,054
Interest expense	40,828		34,458
Loss (gain) on derivatives, net	0		0
Depreciation and amortization	101,832		76,636
General and administrative	0		0
Transaction costs	3,933		12,042
Loss (gain) on extinguishment of debt, net	0		0
Impairment of Asset	0		0
Income (loss) from continuing operations before income taxes and income from unconsolidated entities	49,882		32,918
Income tax (expense) benefit	2,767		(533)
(Loss) income from unconsolidated entities	(6,935)		(15,073)
Income (loss) from continuing operations	45,714		17,312
Gain (loss) on real estate dispositions, net	0		0
Net income	45,714		17,312
Total assets	11,595,907
Outpatient Medical [Member]
Summary of information for reportable segments
Rental income	131,838		117,594
Resident fees and services	0		0
Interest income	1,304		1,264
Other income	313		161
Total revenues	133,455		119,019
Property operating expenses	40,742		37,954
Net Operating Income from Continuing Operations	92,713		81,065
Interest expense	5,744		7,388
Loss (gain) on derivatives, net	0		0
Depreciation and amortization	47,064		42,773
General and administrative	0		0
Transaction costs	1,423		341
Loss (gain) on extinguishment of debt, net	0		0
Impairment of Asset	0		0
Income (loss) from continuing operations before income taxes and income from unconsolidated entities	38,482		30,563
Income tax (expense) benefit	(228)		466
(Loss) income from unconsolidated entities	34		1,032
Income (loss) from continuing operations	38,288		32,061
Gain (loss) on real estate dispositions, net	0		2,749
Net income	38,288		34,810
Total assets	5,059,616
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	58		22
Total revenues	58		22
Property operating expenses	0		0
Net Operating Income from Continuing Operations	58		22
Interest expense	80,782		70,810
Loss (gain) on derivatives, net	0		0
Depreciation and amortization	0		0
General and administrative	45,691		35,138
Transaction costs	0		0
Loss (gain) on extinguishment of debt, net	0		5,064
Impairment of Asset	0		0
Income (loss) from continuing operations before income taxes and income from unconsolidated entities	(126,415)		(110,990)
Income tax (expense) benefit	(497)		(48)
(Loss) income from unconsolidated entities	0		0
Income (loss) from continuing operations	(126,912)		(111,038)
Gain (loss) on real estate dispositions, net	0		0
Net income	(126,912)		(111,038)
Total assets	95,575
Canada [Member]
Summary of information for reportable segments
Total revenues	104,138		$ 57,226
Total assets	$ 2,676,102				$ 1,286,079
Percent Of Assets	0.092				0.044
Percent Of Revenues	0.099		0.064
United Kingdom [Member]
Summary of information for reportable segments
Total revenues	$ 100,555		$ 91,815
Total assets	$ 2,950,387				$ 1,741,973
Percent Of Assets	0.101				0.06
Percent Of Revenues	0.096		0.103
United States [Member]
Summary of information for reportable segments
Total revenues	$ 842,357		$ 745,136
Total assets	$ 23,461,804				$ 25,995,793
Percent Of Assets	0.807				0.896
Percent Of Revenues	0.805		0.833

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