ACQUISITIONS OF REAL ESTATE PROPERTY (Details 2) (ASLG, USD $)	1 Months Ended
	May 31, 2011 property	Jun. 30, 2012	Dec. 31, 2011	May 12, 2011
ASLG
Business acquisition
Senior housing communities acquired	117
Number of development land properties acquired	1
Fair values of the assets acquired and liabilities assumed at the date of acquisition
Land and improvements				$ 341,540,000
Buildings and improvements				2,876,717,000
Acquired lease intangibles				159,610,000
Other assets				215,708,000
Total assets acquired				3,593,575,000
Notes payable and other debt				1,629,212,000
Deferred tax liability				43,466,000
Other liabilities				202,278,000
Total liabilities assumed				1,874,956,000
Net assets acquired				1,718,619,000
Cash acquired				77,718,000
Equity issued				1,376,437,000
Total cash used				264,464,000
Goodwill included in other assets				80,500,000
Contingent consideration liabilities, Fair Value		$ 44,200,000	$ 44,200,000