CONCENTRATION OF CREDIT RISK - Triple-Net Leased Properties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Real estate properties
Other noncash expense	$ (52,489)	$ (26,404)	$ 779
Brookdale Senior Living
Real estate properties
Other noncash expense	$ (42,600)	$ (42,600)	$ (21,300)
Customer Concentration Risk | Revenues | Brookdale Senior Living
Real estate properties
Concentration risk	3.60%	3.90%	4.40%
Customer Concentration Risk | Revenues | Ardent
Real estate properties
Concentration risk	3.20%	3.30%	3.20%
Customer Concentration Risk | Revenues | Kindred
Real estate properties
Concentration risk	3.20%	3.80%	3.50%
Customer Concentration Risk | NOI: | Brookdale Senior Living
Real estate properties
Concentration risk	8.10%	8.60%	9.00%
Customer Concentration Risk | NOI: | Ardent
Real estate properties
Concentration risk	7.10%	7.40%	6.60%
Customer Concentration Risk | NOI: | Kindred
Real estate properties
Concentration risk	7.30%	7.80%	7.10%