BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Investments in Real Estate (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Investments in Real Estate
Impairment of real estate	$ 2,800,000	$ 66,200,000	$ 0	$ 69,000,000	$ 0
Buildings and improvements | Minimum
Investments in Real Estate
Estimated useful lives				15 years
Buildings and improvements | Maximum
Investments in Real Estate
Estimated useful lives				40 years
Furniture, fixtures, and equipment | Minimum
Investments in Real Estate
Estimated useful lives				3 years
Furniture, fixtures, and equipment | Maximum
Investments in Real Estate
Estimated useful lives				5 years