Mortgages Payable (Details) (USD $)	6 Months Ended
	Jun. 30, 2011
Mortgages Payable [Abstract]
Investment in new properties	$ 364,200,000
Mortgages payable deferred financing costs	592,000
Debt Instrument [Line Items]
Principal Balance	58,649,000	[1]
Unamortized Premium (Discount)	957,000
Mortgage Payable Balance	59,606,000
Aviall Services, Inc Maturity 12-1-13 [Member]
Debt Instrument [Line Items]
Stated Interest Rate	6.25%	[2],[3]
Effective Interest Rate	4.95%	[2]
Maturity Date	Dec. 01, 2013	[1],[2]
Principal Balance	12,612,000	[1],[2]
Unamortized Premium (Discount)	458,000	[2]
Mortgage Payable Balance	13,070,000	[2]
Aviall Services, Inc Maturity 9-1-14 [Member]
Debt Instrument [Line Items]
Stated Interest Rate	6.25%	[2],[3]
Effective Interest Rate	4.81%	[2]
Maturity Date	Sep. 01, 2014	[1],[2]
Principal Balance	11,748,000	[1],[2]
Unamortized Premium (Discount)	377,000	[2]
Mortgage Payable Balance	12,125,000	[2]
MeadWestvaco Corporation[Member]
Debt Instrument [Line Items]
Stated Interest Rate	4.69%	[3]
Effective Interest Rate	4.85%
Maturity Date	Jun. 10, 2015	[1]
Principal Balance	23,625,000	[1]
Unamortized Premium (Discount)	(79,000)
Mortgage Payable Balance	23,546,000
T- Mobile USA, Inc. [Member]
Debt Instrument [Line Items]
Stated Interest Rate	5.89%	[3]
Effective Interest Rate	5.14%
Maturity Date	May 06, 2014	[1]
Principal Balance	10,664,000	[1]
Unamortized Premium (Discount)	201,000
Mortgage Payable Balance	$ 10,865,000

[1] The mortgages generally require monthly payments, with a principal payment due at maturity.

[2] There are two mortgages associated with one property occupied by Aviall Services, Inc.

[3] With the exception of the MeadWestvaco Corporation mortgage, the mortgages are at fixed interest rates. The MeadWestvaco Corporation mortgage is at a floating variable interest rate calculated as the sum of the current 1 month LIBOR plus 4.50%, not to exceed an all-in interest rate of 5.5%, based on an interest rate novation agreement entered in connection with this mortgage.