Organization and Description of Business (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Organization and Description of Business
Number of buildings owned	200
Number of states in which the entity owned buildings	34
Area of building (in square feet)	35,300,000
Number of warehouse/distribution buildings	136
Number of light manufacturing buildings	44
Number of flex/office buildings	20
Number of vacant land parcels owned	1
Percentage of buildings leased to tenants	94.00%
Number of tenants to whom buildings are given on lease	180
STAG Industrial Operating Partnership, L.P.
Organization and Description of Business
Ownership interest in Operating Partnership (as a percent)	86.46%	85.29%