SEGMENT INFORMATION - Capital Expenditures (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting Information [Line Items]
Capital expenditures	$ 72,108	$ 1,127,177
Operating Segments | Triple-Net Leased Properties
Segment Reporting Information [Line Items]
Capital expenditures	40,701	457,018
Operating Segments | Senior Living Operations
Segment Reporting Information [Line Items]
Capital expenditures	18,994	282,432
Operating Segments | MOB Operations
Segment Reporting Information [Line Items]
Capital expenditures	$ 12,413	$ 387,727