DISPOSITIONS AND IMPAIRMENTS - Real Estate Assets Held For Sale (Details) $ in Thousands	Jun. 30, 2023 USD ($) property	Dec. 31, 2022 USD ($) property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Properties Held for Sale | property	1,400
Assets held for sale	$ 21,027	$ 44,893
Liabilities related to assets held for sale	2,959	6,492
SHOP
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	21,027	44,852
Liabilities related to assets held for sale	$ 1,910	5,675
Outpatient Medical and Research Portfolio
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Properties Held for Sale | property	460
Assets held for sale	$ 0	41
Liabilities related to assets held for sale	$ 1,049	$ 817
Disposal Group, Held-for-sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Properties Held for Sale | property	2	3
Disposal Group, Held-for-sale, Not Discontinued Operations | SHOP
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Properties Held for Sale | property	2	3
Disposal Group, Held-for-sale, Not Discontinued Operations | Outpatient Medical and Research Portfolio
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Properties Held for Sale | property	0	0