Schedule IV - Mortgage Loans on Real Estate (Details) - USD ($)		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Mortgage Loans on Real Estate [Line Items]
Prior Liens		$ 0
Face Amount of Mortgages		41,618,000
Carrying Amount of Mortgages		41,618,000	[1]	$ 51,000,000
Principal Amount of Loans Subject to delinquent Principal or Interest		11,715,000
Mortgage Loans on Real Estate, Other Required Disclosures [Abstract]
Aggregate tax basis for Federal tax purposes		$ 41,600,000
Interest rate		9.00%		9.00%
Movement in Mortgage Loans on Real Estate [Roll Forward]
Balance at beginning of year		$ 50,988,000		$ 55,155,000	$ 55,648,000
Issuance of loans		368,000
Collection and satisfaction of loans		(10,692,000)		(4,778,000)	(1,057,000)
Amortization of discount		954,000		611,000	564,000
Balance at end of year		41,618,000		$ 50,988,000	$ 55,155,000
Mortgage On Retail Buildings in Philadelphia, PA, Loan One
Mortgage Loans on Real Estate [Line Items]
Prior Liens		0
Face Amount of Mortgages		20,653,000
Carrying Amount of Mortgages	[2]	20,653,000
Principal Amount of Loans Subject to delinquent Principal or Interest		$ 0
Mortgage On Retail Buildings in Philadelphia, PA, Loan One | Interest Rate One
Mortgage Loans on Real Estate [Line Items]
Interest Rate		8.00%
Mortgage On Retail Buildings in Philadelphia, PA, Loan One | Interest Rate Two
Mortgage Loans on Real Estate [Line Items]
Interest Rate		10.00%
Mortgage On Retail Buildings in Philadelphia, PA, Loan One | Maximum
Mortgage Loans on Real Estate [Line Items]
Face Amount of Mortgages		$ 25,000,000.0
Mortgage On Retail Buildings in Philadelphia, PA, Loan Two
Mortgage Loans on Real Estate [Line Items]
Prior Liens		0
Face Amount of Mortgages		9,250,000
Carrying Amount of Mortgages		9,250,000
Principal Amount of Loans Subject to delinquent Principal or Interest		$ 0
Interest Rate		10.00%
Mortgage loan on a shopping center and an adjacent commercial building in Norwalk ,CT
Mortgage Loans on Real Estate [Line Items]
Prior Liens		$ 0
Face Amount of Mortgages		11,715,000
Carrying Amount of Mortgages		11,715,000
Principal Amount of Loans Subject to delinquent Principal or Interest	[3]	$ 11,715,000
Mortgage Loans on Real Estate, Other Required Disclosures [Abstract]
Interest rate		7.00%

[1] For Federal tax purposes, the aggregate tax basis is approximately $41.6 million as of December 31, 2015.

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

[3] This note matured on June 30, 2015, is currently in default, and we have initiated foreclosure proceedings. The estimated net realizable value of the related collateral supports the carrying amount of the note.