SEGMENT INFORMATION - Capital Expenditures (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information
Payments for Capital Improvements	$ 170,613	$ 888,791	$ 481,999	$ 1,269,437
Operating Segments | Triple-Net Leased Properties
Segment Reporting Information
Payments for Capital Improvements	11,832	13,558	33,000	27,805
Operating Segments | Senior Living Operations
Segment Reporting Information
Payments for Capital Improvements	46,349	780,837	129,165	845,290
Operating Segments | Office Operations
Segment Reporting Information
Payments for Capital Improvements	$ 112,432	$ 94,396	$ 319,834	$ 396,342