INVESTMENT IN REAL ESTATE PROPERTIES - Summarized Financial Information for Enlivant Joint Venture (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2022	Jun. 30, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Balance Sheet Amounts
Total assets	$ 5,747,672		$ 5,747,672	$ 5,966,707
Total liabilities	2,691,277		2,691,277	2,587,177
Income Statement Amounts
Total revenues			624,811	569,545	$ 598,569
Other-than-temporary impairment			57,778	164,126	0
Loss from unconsolidated joint venture			(98,032)	(192,081)	(16,599)
Enlivant Joint Venture
Income Statement Amounts
Company’s share of net (loss) income			(32,581)	(17,184)	2,546
Basis adjustments			7,673	10,771	19,145
Other-than-temporary impairment	57,800	$ 164,100	57,778	164,126	0
Loss from unconsolidated joint venture			(98,032)	(192,081)	(16,599)
Enlivant Joint Venture
Balance Sheet Amounts
Total assets	754,220		754,220	467,762
Total liabilities	894,969		894,969	822,063
Member’s deficit	$ (140,749)		(140,749)	(354,301)
Income Statement Amounts
Total revenues			351,073	274,693	299,031
Operating expenses			324,462	265,194	240,331
Net (loss) income			(66,171)	(35,276)	$ 5,196
Funding payments beyond contractual requirements			$ 25,000	$ 20,000