FAIR VALUES OF FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Assets:
Unsecured loans receivable, net	$ 35,408	$ 21,862
Marketable securities	0	76,046
Liabilities:
Redeemable OP unitholder interests	190,500	159,100
Government-sponsored pooled loan investments
Assets:
Marketable securities	63,225	63,115
Carrying Amount
Assets:
Cash and cash equivalents	60,532	55,348
Secured loans receivable, net	726,183	766,641
Unsecured loans receivable, net	35,408	21,862
Liabilities:
Senior notes payable and other debt, gross	11,492,273	10,872,371
Derivative instruments and other liabilities	3,447	2,743
Redeemable OP unitholder interests	190,461	159,134
Carrying Amount | Government-sponsored pooled loan investments
Assets:
Marketable securities	63,225	63,115
Carrying Amount | Marketable securities
Assets:
Marketable securities	0	76,046
Fair Value
Assets:
Cash and cash equivalents	60,532	55,348
Secured loans receivable, net	723,423	774,789
Unsecured loans receivable, net	36,843	23,164
Liabilities:
Senior notes payable and other debt, gross	11,859,324	11,197,131
Derivative instruments and other liabilities	3,447	2,743
Redeemable OP unitholder interests	190,461	159,134
Fair Value | Government-sponsored pooled loan investments
Assets:
Marketable securities	63,225	63,115
Fair Value | Marketable securities
Assets:
Marketable securities	$ 0	$ 76,046