Concentration Of Credit Risk (Details)	12 Months Ended
	Dec. 31, 2014 customer property sqft	Feb. 11, 2015 sqft property
Real Estate Properties [Line Items]
Number of buildings	126	11
Area of real estate property	9,300,000	641,593
Number of tenants accounting for more than 10% of rental revenues	0
Revenue percentage from largest customer	10.00%
Northern New Jersey Or New York City [Member]
Real Estate Properties [Line Items]
Number of buildings	41
Area of real estate property	2,600,000
Percentage accounted by properties of its annualized base rent	27.90%