Subsequent Events (Details) (USD $)			0 Months Ended				6 Months Ended	12 Months Ended	0 Months Ended			0 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Jun. 18, 2012 Common Stock [Member]	Nov. 02, 2011 Common Stock [Member]	Nov. 07, 2011 Common Stock [Member]	Sep. 06, 2011 Common Stock [Member]	Jun. 30, 2012 Common Stock [Member]	Dec. 31, 2011 Common Stock [Member]	Jul. 03, 2012 Property in Havertown, PA [Member]	Jul. 11, 2012 Subsequent Event [Member] Mrs. Baird's [Member] sqft		Jul. 09, 2012 Subsequent Event [Member] Issuance of Equity [Member]	Jul. 09, 2012 Subsequent Event [Member] Common Stock [Member] Issuance of Equity [Member]	Jul. 24, 2012 Preferred Stock Issuance [Member] Series B Preferred Stock [Member]
Subsequent Event [Line Items]
Proceeds from sale of property									$ 600,000
Shares Issued (in shares)													487,500	238,010
Common stock, par value	$ 0.01	$ 0.01
Price per share													$ 10.00
Proceeds from Issuance of Common Stock			30,000,000	14,400,000	700,000	66,000,000	108,100,000	78,100,000				4,600,000
Purchase price of acquired property										6,200,000	[1]
Square feet of acquired property										75,050
Proceeds from Issuance of stock							30,328,000							3,000,000
Proceeds from Issuance of stock, net														$ 2,900,000
Preferred Stock, Dividend Rate, Percentage														7.00%
Annualized rate of dividend (per share)														$ 0.742
Liquidation Preference Per Share														$ 10.60
Convertible conversion price														$ 10.60
Redemption price per share														$ 10.60
Redemption Premium Percent														1.00%

[1] Original purchase price of the Contributed Properties and contract purchase price of all other properties, in each case excluding acquisition and transaction-related costs. Acquisition and transaction-related costs include legal and various other closing costs incurred in connection with acquiring investment properties.