Loans Receivable (Details) $ in Thousands		1 Months Ended	6 Months Ended		12 Months Ended
		Jun. 30, 2015 USD ($)	Jun. 30, 2015 USD ($) class_of_financing	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($) portfolio_segment type_of_financing	Dec. 31, 2013 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan carrying-value	[1]	$ 108,309	$ 108,309		$ 105,635
Number of types of financing receivable | type_of_financing					2
Number of Portfolio Segments | portfolio_segment					1
Number of classes of financing receivable | class_of_financing			1
Westmont, Illinios [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan carrying-value	[1],[2]	12,469	$ 12,469		$ 12,152
Interest rate of mortgage loans	[2]		6.45%		6.45%
Impaired financing receivable, interest income, cash basis method			$ 0	$ 853
Average recorded investment			12,671	$ 12,514
Unpaid principal balance		30,611	30,611
Southfield, Michigan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan carrying-value	[1],[3]	0	$ 0		$ 3,296
Interest rate of mortgage loans	[3]		4.55%		4.55%
Impaired financing receivable, interest income, cash basis method			$ 14
Kennewick, Washington [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan carrying-value	[1]	85,364	$ 85,364		$ 85,254
Interest rate of mortgage loans			9.00%		9.00%
Oklahoma City, Oklahoma [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan carrying-value	[1],[4]	8,474	$ 8,474		$ 0
Interest rate of mortgage loans	[4]		11.50%		11.50%
Oklahoma City, Oklahoma [Member] | Tenant-in-Common [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan carrying-value		$ 8,420	$ 8,420
Ownership percentage		40.00%	40.00%
Austin, Texas [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan carrying-value	[1],[5]	$ 0	$ 0		$ 2,800
Interest rate of mortgage loans	[5]		16.00%		16.00%
Proceeds from Collection of Loans Receivable		3,545
Other Loan Locations [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan carrying-value	[1]	$ 2,002	$ 2,002		$ 2,133
Interest rate of mortgage loans			8.00%		8.00%
Loans Receivable [Member] | Westmont, Illinios [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivable impairment charge						$ 13,939

[1] Loan carrying value includes accrued interest and is net of origination costs and loan losses, if any.

[2] Borrowers are in default and the Company commenced foreclosure proceedings. The tenant at the office property constituting the collateral terminated its lease. The Company recognized an impairment of $13,939 during 2013. During the six months ended June 30, 2015 and 2014, the Company recognized $0 and $853 of interest income relating to the impaired loan, respectively, and the loan had an average recorded investment value of $12,671 and $12,514, respectively. At June 30, 2015, the impaired loan receivable had a contractual unpaid balance of $30,611.

[3] In April 2015, the Company acquired the office property collateral from the borrower. During the six months ended June 30, 2015, the Company recognized $14 of interest income relating to the impaired loan

[4] In June 2015, the Company loaned a tenant-in-common $8,420. The loan is secured by the tenant-in-common's interest in an office property, in which the Company has a 40% interest.

[5] In June 2015, the borrower satisfied the loan with a $3,545 payment, which included yield maintenance.