LOANS RECEIVABLE AND INVESTMENTS - Narrative 2 (Details)	1 Months Ended			3 Months Ended	6 Months Ended		12 Months Ended
	Apr. 30, 2016 USD ($) loan	Feb. 29, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) loan	Dec. 31, 2014 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sale of loans	$ 5,000,000						$ 97,000,000
Investment in loans receivable and other					$ 152,450,000	$ 55,659,000
Gain on repayment of loans receivable							$ 1,900,000
Unsecured Debt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan							1
Debt instrument, face amount							$ 20,000,000.0
Secured Debt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan	1						1
Debt instrument, face amount							$ 78,400,000.0
Secured mortgage loans and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recognized gain on sale of investments				$ 100,000	$ 100,000
Investment in loans receivable and other		$ 140,000,000
Secured loan, stated interest rate, percentage		9.95%
Number of loans sold | loan							3
Non-mortgage loans receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans sold | loan							1
Corporate Debt Securities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recognized gain on sale of investments			$ 5,800,000
Available-for-sale securities, amortized cost basis			71,000,000			$ 71,000,000
Proceeds from sale of investment			$ 76,800,000
Unrealized gain on investment								$ 5,000,000