Mortgages Payable (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2012		Dec. 31, 2011
Mortgages Payable [Abstract]
Assumed mortgage payables			$ 67,400,000
Net premiums recorded upon assumption of mortgages			820,000
Deferred financing costs originally recorded for mortgages payable			917,000
Deferred financing costs remaining balance at period end	669,000		751,000
Debt Instrument [Line Items]
Remaining Principal Balance	56,344,000	[1]	67,150,000	[1]
Amortized Premium (Discount) Balance	534,000		631,000
Mortgage Payable Balance	56,878,000		67,781,000
Maturity 12-1-13 [Member]
Debt Instrument [Line Items]
Maturity Date	Dec. 01, 2013	[1],[2]	Dec. 01, 2013	[1],[2]
Stated Interest Rate (in hundredths)	6.25%	[2],[3]	6.25%	[2],[3]
Effective Interest Rate (in hundredths)	4.62%	[2]	4.63%	[2]
Remaining Principal Balance	12,307,000	[1],[2]	12,410,000	[1],[2]
Amortized Premium (Discount) Balance	285,000	[2]	314,000	[2]
Mortgage Payable Balance	12,592,000	[2]	12,724,000	[2]
Number of properties occupied by applicable tenant	1		1
Maturity 9-1-14 [Member]
Debt Instrument [Line Items]
Maturity Date	Sep. 01, 2014	[1],[2]	Sep. 01, 2014	[1],[2]
Stated Interest Rate (in hundredths)	6.25%	[2],[3]	6.25%	[2],[3]
Effective Interest Rate (in hundredths)	5.10%	[2]	5.09%	[2]
Remaining Principal Balance	11,632,000	[1],[2]	11,671,000	[1],[2]
Amortized Premium (Discount) Balance	312,000	[2]	359,000	[2]
Mortgage Payable Balance	11,944,000	[2]	12,030,000	[2]
Number of properties occupied by applicable tenant	1		1
Maturity 5-6-12 [Member]
Debt Instrument [Line Items]
Maturity Date			May 06, 2012	[1]
Stated Interest Rate (in hundredths)			5.89%	[3]
Effective Interest Rate (in hundredths)			5.19%
Remaining Principal Balance			10,664,000	[1]
Amortized Premium (Discount) Balance			26,000
Mortgage Payable Balance			10,690,000
Maturity 6-10-15 [Member]
Debt Instrument [Line Items]
Maturity Date	Jun. 10, 2015	[1]	Jun. 10, 2015	[1]
Stated Interest Rate (in hundredths)	4.75%	[3]	4.73%	[3]
Effective Interest Rate (in hundredths)	4.85%		4.84%
Remaining Principal Balance	23,625,000	[1]	23,625,000	[1]
Amortized Premium (Discount) Balance	(63,000)		(68,000)
Mortgage Payable Balance	23,562,000		23,557,000
Floating variable interest rate, variable rate basis	1 month LIBOR
Floating variable interest rate, basis spread on variable rate (in hundredths)	4.50%		4.50%
Mortgage interest rate payable, maximum (in hundredths)	5.50%		5.50%
Effective Rate 8.26% Note 1 [Member]
Debt Instrument [Line Items]
Maturity Date	Dec. 28, 2013	[1],[4],[5]	Dec. 28, 2013	[1],[4],[5]
Stated Interest Rate (in hundredths)	8.26%	[3],[4],[5]	8.26%	[3],[4],[5]
Effective Interest Rate (in hundredths)	8.26%	[4],[5]	8.26%	[4],[5]
Remaining Principal Balance	4,510,000	[1],[4],[5]	4,510,000	[1],[4],[5]
Amortized Premium (Discount) Balance	0	[4],[5]	0	[4],[5]
Mortgage Payable Balance	4,510,000	[4],[5]	4,510,000	[4],[5]
Number of properties occupied by applicable tenant	1
Effective Rate 8.26% Note 2 [Member]
Debt Instrument [Line Items]
Maturity Date	Dec. 28, 2013	[1],[4],[5]	Dec. 28, 2013	[1],[4],[5]
Stated Interest Rate (in hundredths)	8.26%	[3],[4],[5]	8.26%	[3],[4],[5]
Effective Interest Rate (in hundredths)	8.26%	[4],[5]	8.26%	[4],[5]
Remaining Principal Balance	4,270,000	[1],[4],[5]	4,270,000	[1],[4],[5]
Amortized Premium (Discount) Balance	0	[4],[5]	0	[4],[5]
Mortgage Payable Balance	4,270,000	[4],[5]	4,270,000	[4],[5]
Number of properties occupied by applicable tenant	1
Effective Rate 8.26% Notes 1 and 2 [Member]
Debt Instrument [Line Items]
Note receivable assumed in connection with 2011 acquisition			$ 8,800,000
Assumed Note Receivable Stated Interest Rate (in hundredths)			8.14%

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

[2] These are mortgages associated with one property occupied by the applicable tenant.

[3] The mortgages are at fixed interest rates, with the exception of the mortgage maturing on June 10, 2015 that 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%.

[4] As part of the assumption of these mortgages payable related to our 2011 acquisitions, we also assumed an $8.8 million note receivable, upon which we will receive interest income at a stated rate of 8.14% through December 28, 2013.

[5] Mortgages associated with one property occupied by the applicable tenant.