INVESTMENTS IN UNCONSOLIDATED ENTITIES (Details) (USD $)	3 Months Ended		9 Months Ended			1 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Mar. 31, 2013	Mar. 31, 2013 Two Medical Office Buildings Acquired March 2013 property	Sep. 30, 2013 Unconsolidated Properties property	Dec. 31, 2012 Unconsolidated Properties property	Sep. 30, 2013 Unconsolidated Properties Minimum	Dec. 31, 2012 Unconsolidated Properties Minimum	Sep. 30, 2013 Unconsolidated Properties Maximum	Dec. 31, 2012 Unconsolidated Properties Maximum	Sep. 30, 2013 ATRIA	Dec. 31, 2012 ATRIA
Equity Method Investments and Joint Ventures [Abstract]
Management fees earned in connection with unconsolidated entities	$ 1,500,000	$ 2,000,000	$ 4,100,000	$ 5,700,000
Equity method investments
Ownership interests accounted for under the equity method (as a percent)					5.00%				5.00%	5.00%	25.00%	25.00%	34.00%	34.00%
Number of properties accounted for under equity method							53	55
Number of real estate properties						2
Purchase of joint venture interests						55,200,000
Gain on re-measurement of equity method investments						$ 1,300,000