LOANS RECEIVABLE AND INVESTMENTS (Details) $ in Thousands	1 Months Ended	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2015 USD ($) loan	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($) loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Marketable securities	$ 0	$ 0	$ 0		$ 76,046
Available-for-sale securities, unrealized gain (loss)	1,503	1,503	1,503		6,784
Secured loans, unsecured loans, and other available-for-sale securities, carrying amount	824,816	824,816	824,816		927,664
Secured loans, unsecured loans, and other available-for-sale securities, amortized cost	823,313	823,313	823,313		920,880
Secured loans, unsecured loans, and other available-for-sale securities, fair value	823,491	823,491	823,491		937,114
Purchase of marketable securities			0	$ 46,689
Investment in loans receivable and other			55,659	$ 44,488
Proceeds from sale of loans			86,200		55,900
Gain on the repayment of loans receivable			1,500		5,200
Total proceeds from sale or maturity of marketable securities					22,300
Recognized gain on sale of marketable securities					600
Secured loans receivable and investments, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Available-for-sale securities, unrealized gain (loss)	1,503	1,503	1,503		1,738
Secured loans, unsecured loans, and other available-for-sale securities, carrying amount	789,408	789,408	789,408		829,756
Secured loans, unsecured loans, and other available-for-sale securities, amortized cost	787,905	787,905	787,905		828,018
Secured loans, unsecured loans, and other available-for-sale securities, fair value	786,648	786,648	786,648		837,904
Other Assets
Accounts, Notes, Loans and Financing Receivable [Line Items]
Available-for-sale securities, unrealized gain (loss)	0	0	0		5,046
Secured loans, unsecured loans, and other available-for-sale securities, carrying amount	35,408	35,408	35,408		97,908
Secured loans, unsecured loans, and other available-for-sale securities, amortized cost	35,408	35,408	35,408		92,862
Secured loans, unsecured loans, and other available-for-sale securities, fair value	36,843	36,843	36,843		99,210
Government-sponsored pooled loan investments
Accounts, Notes, Loans and Financing Receivable [Line Items]
Marketable securities	63,225	63,225	63,225		63,115
Available-for-sale securities, amortized cost	61,722	61,722	61,722		61,377
Available-for-sale securities, unrealized gain (loss)	1,503	1,503	1,503		1,738
Investment in loans receivable and other					38,700
Marketable securities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Marketable securities					76,046
Available-for-sale securities, amortized cost					71,000
Available-for-sale securities, unrealized gain (loss)					5,046
Senior unsecured corporate bonds
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchase of marketable securities					71,000
Carrying value of investment	71,000	71,000	71,000
Proceeds from sale of investment	76,800
Recognized gain on sale of investments		5,800	5,800
Unrealized gains of investments		5,000
Marketable equity securities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchase of marketable securities					21,700
Secured mortgage loans and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Secured loan receivable, carrying amount and amortized cost	726,183	726,183	726,183		766,641
Mortgage loans and other, fair value	723,423	723,423	$ 723,423		$ 774,789
Number of loans sold | loan			1		3
Secured mortgage loans and other | Mezzanine Loan Investment Due 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investment in loans receivable and other					$ 425,000
Secured loan receivable, interest rate					8.10%
Unsecured loans receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Secured loan receivable, carrying amount and amortized cost	35,408	35,408	$ 35,408		$ 21,862
Mortgage loans and other, fair value	$ 36,843	$ 36,843	$ 36,843		$ 23,164
Number of loans sold | loan			1		2