SEGMENT INFORMATION - Capital Expenditures (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Capital expenditures	$ 1,363,289	$ 960,171	$ 2,723,258	$ 1,311,646
Triple-Net Leased Properties
Segment Reporting Information [Line Items]
Capital expenditures	1,318,868	99,590	1,878,857	349,022
Senior Living Operations
Segment Reporting Information [Line Items]
Capital expenditures	34,104	853,723	345,910	932,903
MOB Operations
Segment Reporting Information [Line Items]
Capital expenditures	$ 10,317	$ 6,858	$ 498,491	$ 29,721