Summary of Significant Accounting Policies - Concentration of credit risk (Details)	12 Months Ended
	Dec. 31, 2012
Concentration Risk [Line Items]
Cash on deposit, number of financial institutions	2
Cash on deposit, number of financial institutions which had deposits in excess of current federally insured limits	0
Texas
Concentration Risk [Line Items]
Number of owned properties (in number of properties)	3
North Carolina
Concentration Risk [Line Items]
Number of owned properties (in number of properties)	1
Georgia
Concentration Risk [Line Items]
Number of owned properties (in number of properties)	1
Gross annualized rental revenues by industry | Tractor supply company
Concentration Risk [Line Items]
Concentration risk, percentage	21.00%
Gross annualized rental revenues by industry | CVS caremark corporation
Concentration Risk [Line Items]
Concentration risk, percentage	21.00%
Gross annualized rental revenues by industry | Walgreen co.
Concentration Risk [Line Items]
Concentration risk, percentage	21.00%
Customer concentration risk | Gross annualized rental revenues by industry | Drugstore industry
Concentration Risk [Line Items]
Concentration risk, percentage	42.00%
Customer concentration risk | Gross annualized rental revenues by industry | Home and garden industry
Concentration Risk [Line Items]
Concentration risk, percentage	21.00%
Credit concentration risk | Gross annualized rental revenues by industry | Texas
Concentration Risk [Line Items]
Concentration risk, percentage	44.00%
Credit concentration risk | Gross annualized rental revenues by industry | North Carolina
Concentration Risk [Line Items]
Concentration risk, percentage	14.00%
Credit concentration risk | Gross annualized rental revenues by industry | Georgia
Concentration Risk [Line Items]
Concentration risk, percentage	11.00%