FAIR VALUES OF FINANCIAL INSTRUMENTS (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Assets:
Unsecured loans receivable, net	$ 66,003	$ 38,512
Liabilities:
Redeemable OP unitholder interests	117,300	111,600
Carrying Amount
Assets:
Cash and cash equivalents	59,791	94,816
Secured loans receivable, net	354,219	354,775
Unsecured loans receivable, net	39,805	38,512
Marketable Securities	48,053	21,454
Liabilities:
Senior notes payable and other debt, gross	9,442,636	9,320,477
Derivative instruments and other liabilities	10,744	11,105
Redeemable OP unitholder interests	117,261	111,607
Fair Value
Assets:
Cash and cash equivalents	59,791	94,816
Secured loans receivable, net	353,117	355,223
Unsecured loans receivable, net	41,939	40,473
Marketable Securities	48,053	21,454
Liabilities:
Senior notes payable and other debt, gross	9,655,319	9,405,259
Derivative instruments and other liabilities	10,744	11,105
Redeemable OP unitholder interests	$ 117,261	$ 111,607