SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) variableInterestEntity Segment Investment	Dec. 31, 2020 USD ($) Investment	Jan. 01, 2019 USD ($)
Accounting Policies [Line Items]
Number of investments in loans accounted for as real estate joint ventures | Investment	0	0
Extension period for tenant relationship intangible assets	25 years
Assets held for sale	$ 0	$ 0
Restricted cash	3,890,000	6,447,000
Restricted cash obligations	$ 3,200,000	3,500,000
Number of reportable segments | Segment	1
Equity	$ 3,379,530,000	3,409,228,000
Primary beneficiary
Accounting Policies [Line Items]
Number of variable interest entities | variableInterestEntity	0
Land improvements | Minimum
Accounting Policies [Line Items]
Estimated useful lives of assets	15 years
Land improvements | Maximum
Accounting Policies [Line Items]
Estimated useful lives of assets	20 years
Buildings and building improvements | Minimum
Accounting Policies [Line Items]
Estimated useful lives of assets	5 years
Buildings and building improvements | Maximum
Accounting Policies [Line Items]
Estimated useful lives of assets	45 years
Furniture and equipment | Minimum
Accounting Policies [Line Items]
Estimated useful lives of assets	3 years
Furniture and equipment | Maximum
Accounting Policies [Line Items]
Estimated useful lives of assets	10 years
Resident fee and services
Accounting Policies [Line Items]
Grants recognized	$ 500,000	1,800,000
Loss from unconsolidated joint venture
Accounting Policies [Line Items]
Grants recognized		$ 3,500,000
Topic 842 | Cumulative effect
Accounting Policies [Line Items]
Equity			$ (32,500,000)
Accounts receivable			(32,500,000)
Topic 842 | Cumulative effect | Straight-line rental income receivable
Accounting Policies [Line Items]
Accounts receivable			(17,500,000)
Topic 842 | Cumulative effect | Cash rent receivable
Accounting Policies [Line Items]
Accounts receivable			$ (15,000,000)