Description of Business and Principles of Interim Statements - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014 SecurityLoan Billboard acre State Property sqft	Dec. 31, 2013	Jan. 31, 2013 Property
Description of Business [Line Items]
Number of states in which entity operates	10
Self developed multi-tenant properties	5
Commercial real estate properties	36
Gross leasable space	872,000
Land portfolio	10,500
Self developed multi- tenant properties completed	2
Number of commercial mortgage loan investments	3
Number of billboards leased for property	21
Cash and cash equivalents maximum original maturity period	90 days
Restricted Cash	$ 842,508	$ 366,645
Cash held in reserve for property taxes and insurance escrows	241,000
Cash held in escrow related to land transaction	284,000
Number of properties acquired	2		2
Cash Held In Escrow For Exchange Transaction [Member]
Description of Business [Line Items]
Restricted Cash	$ 318,000