Mortgage Loans on Real Estate (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Sep. 30, 2011
Mortgage Loans on Real Estate [Line Items]
Prior Liens	$ 226,898
Face Amount of Mortgages	173,520	10,800
Carrying Amount of Mortgages	84,541
Principal amount of loans subject to delinquent principal or interest	86,995			9,300
Carrying amount
Balance at beginning of period	103,705	58,719	115,419
Additions during period
New mortgage loans	10,000	60,618	6,197
Interest	811	3,106	9,355
Accretion of discount	780	250	0
Deductions during period
Loan loss reserve	(5,000)	0	(72,252)
Collections of principal	(25,755)	0	0
Loan foreclosure	0	(18,988)	0
Balance at close of period	84,541	103,705	58,719
Senior Loans and Mezzanine Loans [Member]
Mortgage Loans on Real Estate [Line Items]
Prior Liens	226,898
Face Amount of Mortgages	106,674
Carrying Amount of Mortgages	84,541
Principal amount of loans subject to delinquent principal or interest	20,149
Borrower A [Member] | Senior Loans [Member] | Retail [Member]
Mortgage Loans on Real Estate [Line Items]
Mortgage loans on real estate rates	0.0573
Final Maturity Date	Sep. 01, 2017
Periodic Payment Terms	Interest only thru 08/30/2012, Interest and principal effective 9/1/2012
Prior Liens	0
Face Amount of Mortgages	33,000
Carrying Amount of Mortgages	27,630
Borrower B [Member] | Mezzanine [Member] | Multi Family [Member]
Mortgage Loans on Real Estate [Line Items]
Mortgage loans on real estate rates	LIBOR+6.0%, Floor 11%
Final Maturity Date	Feb. 01, 2017
Periodic Payment Terms	Interest monthly, principal at maturity
Prior Liens	26,000
Face Amount of Mortgages	5,868
Carrying Amount of Mortgages	5,868
Borrower C [Member] | Mezzanine [Member] | Retail [Member]
Mortgage Loans on Real Estate [Line Items]
Mortgage loans on real estate rates	0.11
Final Maturity Date	Jun. 01, 2013
Periodic Payment Terms	Interest monthly, principal at maturity
Prior Liens	51,750
Face Amount of Mortgages	12,800
Carrying Amount of Mortgages	10,000
Borrower D [Member] | Mezzanine [Member] | Retail [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Rate	10.00%
Final Maturity Date	Oct. 01, 2017
Periodic Payment Terms	Interest monthly, principal at maturity
Prior Liens	139,805
Face Amount of Mortgages	31,700
Carrying Amount of Mortgages	31,700
Borrower E [Member] | Mezzanine [Member] | Mixed Use [Member]
Mortgage Loans on Real Estate [Line Items]
Mortgage loans on real estate rates	LIBOR+10.0%,Floor 14%
Final Maturity Date On Demand	on demand (loan in default)
Periodic Payment Terms	Interest monthly, principal at maturity
Prior Liens	0
Face Amount of Mortgages	12,500
Carrying Amount of Mortgages	9,343
Principal amount of loans subject to delinquent principal or interest	9,343
Borrower F [Member] | Mezzanine [Member] | Mixed Use [Member]
Mortgage Loans on Real Estate [Line Items]
Mortgage loans on real estate rates	LIBOR+8.0%, Floor 12%
Final Maturity Date On Demand	on demand (loan in default)
Periodic Payment Terms	Interest monthly, principal at maturity
Prior Liens	9,343
Face Amount of Mortgages	10,806
Carrying Amount of Mortgages	0
Principal amount of loans subject to delinquent principal or interest	10,806
Borrower G [Member] | Investments in and advances to joint ventures [Member]
Mortgage Loans on Real Estate [Line Items]
Mortgage loans on real estate rates	LIBOR+7.0%, Floor 12%
Final Maturity Date On Demand	on demand (loan in default)
Periodic Payment Terms	Interest monthly, principal at maturity
Prior Liens	0
Face Amount of Mortgages	66,846
Carrying Amount of Mortgages	0
Principal amount of loans subject to delinquent principal or interest	$ 66,846