Real Property Acquisitions and Development (Details 1) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011
Senior housing - triple net [Member]
Estimated Fair Value of Allocated Purchase Price of Asset and Liabilities
Land and land improvements	$ 79,325	[1]	$ 210,956
Buildings and improvements	935,036	[1]	2,991,317
Total assets acquired	1,014,361	[1],[2]	3,202,273
Assumed debt	(86,186)	[1]	(93,425)
Accrued expenses and other liabilities	(3,340)	[1]	(75,144)
Total liabilities assumed	(89,526)	[1]	(168,569)
Capital in excess of par	1,024	[1]	0
Noncontrolling interests	(16,826)	[1]	0
Non-cash acquisition related activity	(310)	[1]	0
Cash disbursed for acquisitions	908,723	[1]	3,033,704
Construction in progress additions	131,579	[1]	121,382
Less: Capitalized Interest	(4,228)	[1]	(4,077)
Cash disbursed for construction in progress	127,351	[1]	117,305
Capital improvements to existing properties	48,450	[1]	16,453
Total cash invested in real property	1,084,524	[1]	3,167,462
Cash Acquired from Acquisition	2,031
Total purchase price	777,916
Senior housing - operating [Member]
Estimated Fair Value of Allocated Purchase Price of Asset and Liabilities
Land and land improvements	46,391	[3]	71,610
Buildings and improvements	450,255	[3]	968,727
Acquired lease intangibles	39,875	[3]	88,285
Restricted cash	0	[3]	8,186
Investment in unconsolidated entities	0	[3]	0
Receivables and other assets	2,247	[3]	18,415
Total assets acquired	538,768	[3],[4]	1,155,223	[4]
Assumed debt	(8,684)	[3]	(585,656)
Accrued expenses and other liabilities	(5,480)	[3]	(39,044)
Total liabilities assumed	(14,164)	[3]	(624,700)
Capital in excess of par	0	[3]	(6,017)
Noncontrolling interests	(2,054)	[3]	(27,560)
Non-cash acquisition related activity	0	[3]	(27,298)
Cash disbursed for acquisitions	522,550	[3]	469,648
Capital improvements to existing properties	13,325	[3]	14,847
Total cash invested in real property	535,875	[3]	484,495
Cash Acquired from Acquisition	4,369		34,342
Total purchase price	330,013
Medical facilities [Member]
Estimated Fair Value of Allocated Purchase Price of Asset and Liabilities
Land and land improvements	53,493	[5]	7,711
Buildings and improvements	487,255	[5]	303,848
Acquired lease intangibles	93,392	[5]	1,126
Restricted cash	975	[5]	0
Receivables and other assets	4,311	[5]	0
Total assets acquired	639,426	[5]	312,685
Assumed debt	(238,589)	[5]	(48,801)
Accrued expenses and other liabilities	(18,075)	[5]	(568)
Total liabilities assumed	(256,664)	[5]	(49,369)
Noncontrolling interests			(5,853)
Non-cash acquisition related activity	(880)	[5]	0
Cash disbursed for acquisitions	381,882	[5]	257,463
Construction in progress additions	94,462	[5]	138,898
Less: Capitalized Interest	(2,885)	[5]	(6,013)
Less: Accruals	(4,567)	[5],[6]	(33,451)	[6]
Cash disbursed for construction in progress	87,010	[5]	99,434
Capital improvements to existing properties	30,505	[5]	21,590
Total cash invested in real property	499,397	[5]	378,487
Total purchase price	$ 486,014

[1] (1) Includes acquisitions with an aggregate purchase price of $777,916,000 for which the allocation of the purchase price consideration is preliminary and subject to change.

[2] (2) Excludes $2,031,000 of cash acquired during the nine months ended September 30, 2012.

[3] (2) Includes acquisitions with an aggregate purchase price of $330,013,000 for which the allocation of the purchase price consideration is preliminary and subject to change.

[4] (1) Excludes $4,369,000 and $34,342,000 of cash acquired during the nine months ended September 30, 2012 and 2011, respectively.

[5] (2) Includes acquisitions with an aggregate purchase price of $486,014,000 for which the allocation of the purchase price consideration is preliminary and subject to change.

[6] (1) Represents non-cash accruals for amounts to be paid in future periods relating to properties that converted in the periods noted above.