Schedule IV - Mortgage Loans on Real Estate (Details) - Conventional Mortgage Loan [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($)
Mortgage Loans on Real Estate [Line Items]
Face Amount of Mortgages	$ 26,115
Carrying Amount of Mortgages	24,238
Principal Amount of Loans Subject to Delinquent Principal or Interest	$ 0
Mt. Airy, MD [Member] | Bank of America, N.A. [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Rate	6.42%
Face Amount of Mortgages	$ 2,731
Carrying Amount of Mortgages	3,008
Principal Amount of Loans Subject to Delinquent Principal or Interest	$ 0
Evansville, IN [Member] | CVS Caremark Corporation [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Rate	6.22%
Face Amount of Mortgages	$ 2,763
Carrying Amount of Mortgages	3,050
Principal Amount of Loans Subject to Delinquent Principal or Interest	$ 0
Greensboro, GA [Member] | CVS Caremark Corporation [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Rate	6.52%
Face Amount of Mortgages	$ 1,049
Carrying Amount of Mortgages	1,177
Principal Amount of Loans Subject to Delinquent Principal or Interest	$ 0
Shelby Twp., MI [Member] | CVS Caremark Corporation [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Rate	5.98%
Face Amount of Mortgages	$ 2,106
Carrying Amount of Mortgages	2,278
Principal Amount of Loans Subject to Delinquent Principal or Interest	$ 0
Bensalem, PA [Member] | Koninilijke Ahold N.V. [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Rate	7.24%
Face Amount of Mortgages	$ 1,706
Carrying Amount of Mortgages	1,886
Principal Amount of Loans Subject to Delinquent Principal or Interest	$ 0
Framingham, MA [Member] | Lowes Companies, Inc. [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Rate	5.87%
Face Amount of Mortgages	$ 5,799
Carrying Amount of Mortgages	1,742
Principal Amount of Loans Subject to Delinquent Principal or Interest	$ 0
Dallas, TX [Member] | Walgreen Co. [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Rate	6.46%
Face Amount of Mortgages	$ 2,635
Carrying Amount of Mortgages	2,947
Principal Amount of Loans Subject to Delinquent Principal or Interest	$ 0
Nacogdoches, TX [Member] | Walgreen Co. [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Rate	6.80%
Face Amount of Mortgages	$ 2,874
Carrying Amount of Mortgages	3,272
Principal Amount of Loans Subject to Delinquent Principal or Interest	$ 0
Rosemead, CA [Member] | Walgreen Co. [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Rate	6.26%
Face Amount of Mortgages	$ 4,032
Carrying Amount of Mortgages	4,458
Principal Amount of Loans Subject to Delinquent Principal or Interest	$ 0
Philadelphia, PA [Member] | TJX [Member]
Mortgage Loans on Real Estate [Line Items]
Interest Rate	5.57%
Face Amount of Mortgages	$ 420
Carrying Amount of Mortgages	420
Principal Amount of Loans Subject to Delinquent Principal or Interest	$ 0