Real Property Acquisitions and Development (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Senior housing - triple net [Member]
Estimated Fair Value of Allocated Purchase Price of Asset and Liabilities
Land and land improvements	$ 5,950	$ 8,990
Buildings and improvements	89,333	105,340
Acquired lease intangibles	0	0
Restricted cash	0	0
Investment in unconsolidated entities	0	0
Receivables and other assets	0	329
Cash and cash equivalents	0	0
Total assets acquired	95,283	114,659
Secured debt	0	(7,054)
Accrued expenses and other liabilities	(232)	(1,655)
Total liabilities assumed	(232)	(8,709)
Less: Capitalized Interest	(1,242)	(976)
Cash disbursed for acquisitions	95,051	105,950
Cash disbursed for construction in progress	37,225	30,916
Construction in progress additions	38,467	31,892
Capital improvements to existing properties	9,948	3,235
Total cash invested in real property	142,224	140,101
Senior housing - operating [Member]
Estimated Fair Value of Allocated Purchase Price of Asset and Liabilities
Land and land improvements	18,980	71,610
Buildings and improvements	174,467	968,727
Acquired lease intangibles	16,656	88,285
Restricted cash	0	8,185
Investment in unconsolidated entities	0	11,516
Receivables and other assets	1,182	3,455
Total assets acquired	211,285	1,151,778
Secured debt	0	(585,657)
Accrued expenses and other liabilities	(1,649)	(39,043)
Total liabilities assumed	(1,649)	(624,700)
Capital in excess of par	0	(6,017)
Noncontrolling interests	(2,054)	(27,559)
Cash disbursed for acquisitions	207,582	468,856
Capital improvements to existing properties	3,040	2,267
Non-cash acquisition related activity	0	(24,646)
Total cash invested in real property	210,622	471,123
Cash Acquired from Acquisition	1,619	34,973
Medical facilities [Member]
Estimated Fair Value of Allocated Purchase Price of Asset and Liabilities
Land and land improvements	9,509	6,981
Buildings and improvements	320,481	0
Acquired lease intangibles	39,619	0
Receivables and other assets	4,158	0
Total assets acquired	373,767	6,981
Secured debt	(172,856)	0
Accrued expenses and other liabilities	(9,255)	0
Total liabilities assumed	(182,111)	0
Less: Capitalized Interest	(1,178)	(3,689)
Cash disbursed for acquisitions	191,656	6,981
Cash disbursed for construction in progress	18,627	59,771
Construction in progress additions	40,557	82,590
Capital improvements to existing properties	7,071	5,376
Non-cash acquisition related activity	(20,752)	(19,130)
Total cash invested in real property	217,354	72,128
Total purchase price	$ 363,136