SEGMENT INFORMATION - Capital Expenditures (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information
Payments for Capital Improvements	$ 116,744	$ 110,830	$ 205,225	$ 311,386
Operating Segments | Triple-Net Leased Properties
Segment Reporting Information
Payments for Capital Improvements	8,921	13,483	17,139	21,168
Operating Segments | Senior Living Operations
Segment Reporting Information
Payments for Capital Improvements	51,156	30,932	99,873	82,816
Operating Segments | Office Operations
Segment Reporting Information
Payments for Capital Improvements	$ 56,667	$ 66,415	$ 88,213	$ 207,402