Schedule IV - Mortgage Loans on Real Estate (Details) (USD $)	12 Months Ended						12 Months Ended	0 Months Ended	12 Months Ended			0 Months Ended	12 Months Ended						12 Months Ended		0 Months Ended	12 Months Ended	0 Months Ended
	Dec. 31, 2012		Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Mortgage On Retail Buildings in Philadelphia, PA, Loan One [Member]		Dec. 31, 2012 Mortgage On Retail Buildings in Philadelphia, PA, Loan Two [Member]	Aug. 04, 2006 Second Mortgage On Hotel In San Jose, CA [Member]	Dec. 31, 2012 Second Mortgage On Hotel In San Jose, CA [Member]		Dec. 31, 2011 Second Mortgage On Hotel In San Jose, CA [Member]	Feb. 02, 2011 Mortgage On Restaurant In Rockville, MD [Member]	Dec. 31, 2012 Mortgage On Restaurant In Rockville, MD [Member]		Dec. 31, 2012 Mortgage loan on a shopping center and an adjacent commercial building in Norwalk ,CT [Member]		Jun. 30, 2011 Mortgage loan on a shopping center and an adjacent commercial building in Norwalk ,CT [Member]	Dec. 31, 2012 Maximum [Member] Mortgage On Retail Buildings in Philadelphia, PA, Loan One [Member]	Dec. 31, 2012 Interest Rate One [Member] Mortgage On Retail Buildings in Philadelphia, PA, Loan One [Member]	Dec. 31, 2012 Interest Rate Two [Member] Mortgage On Retail Buildings in Philadelphia, PA, Loan One [Member]	Feb. 02, 2011 Extension Option One [Member] Mortgage On Restaurant In Rockville, MD [Member]	Dec. 31, 2012 Extension Option One [Member] Mortgage loan on a shopping center and an adjacent commercial building in Norwalk ,CT [Member]	Feb. 02, 2011 Extension Option Two [Member] Mortgage On Restaurant In Rockville, MD [Member]
Mortgage Loans on Real Estate [Line Items]
Mortgage Loans on Real Estate, Participation Plus Interest Rate, Interest Rate							10.00%												8.00%	10.00%
Prior Liens	$ 35,000,000				$ 0		$ 0		$ 35,000,000	[1],[2]			$ 0	[3]	$ 0	[4]
Face Amount of Mortgages	57,777,000				20,286,000		9,250,000		12,914,000	[1]	14,200,000		3,612,000	[3]	11,715,000	[4]	11,900,000	25,000,000
Carrying Amount of Mortgages	55,648,000	[5]	56,000,000		20,286,000	[6]	9,250,000		10,785,000	[1]			3,612,000	[3]	11,715,000	[4]
Principal Amount of Loans Subject to delinquent Principal or Interest	0				0		0		0	[1]			0	[3]	0	[4]
Mortgage Loans on Real Estate, Other Required Disclosures [Abstract]
Mortgage Loans on Real Estate, Federal Income Tax Basis	57,800,000
Payments of Principal and Interest Based on Amortization Schedule, Period								15 years				30 years
Mortgage Loans on Real Estate, Interest Rate, Increase in Subsequent Year of Extension																					1.00%
Extension Option Period																					1 year	1 year	3 years
Mortgage Loans on Real Estate, Interest Rate	9.40%		9.20%					14.00%	9.00%				9.00%		6.00%						12.00%	7.00%
Movement in Mortgage Loans on Real Estate [Roll Forward]
Balance at beginning of year	55,967,000		44,813,000	48,336,000
Issuance of loans	70,000		130,000	14,787,000
Deconsolidation of VIE			18,311,000
Collection and satisfaction of loans	(1,161,000)		(7,598,000)	(464,000)
Amortization of discount /loan fee	772,000		311,000	465,000
Consolidation of VIE				(18,311,000)
Balance at end of year	$ 55,648,000		$ 55,967,000	$ 44,813,000

[1] This note was amended on August 4, 2006. The amended note decreased the interest from 14% to 9% per annum, and requires monthly payments of principal and interest based on 15-year amortization schedule.

[2] We do not hold the first mortgage loan on this property. Accordingly, the amount of the prior lien at December 31, 2012 is estimated.

[3] Beginning February 1, 2011, the note requires monthly payments of principal and interest based on a 30-year amortization schedule. The borrower has one, three-year extension option with an interest rate of 12% which increases 1% in each subsequent year of the extension term.

[4] The loan is subject to a one year extension option with an interest rate of 7% .

[5] For Federal tax purposes, the aggregate tax basis is approximately $57.8 million as of December 31, 2012.

[6] This mortgage is available for up to $25.0 million.