SEGMENT INFORMATION - Capital Expenditures (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Capital expenditures	$ 232,792	$ 129,527	$ 1,359,969	$ 351,475
Triple-Net Leased Properties
Segment Reporting Information [Line Items]
Capital expenditures	102,971	57,380	559,989	249,432
Senior Living Operations
Segment Reporting Information [Line Items]
Capital expenditures	29,374	62,317	311,806	79,180
MOB Operations
Segment Reporting Information [Line Items]
Capital expenditures	$ 100,447	$ 9,830	$ 488,174	$ 22,863