Commitments and Contingencies (Details) (One-time incentive fee, Columbus Nova, USD $)	Jun. 30, 2012
One-time incentive fee \| Columbus Nova
Commitments and Contingencies
Internal rate of return (as a percent)	10.00%
Percentage of return earned by entity upon achieving a 10% internal rate of return by the entity	20.00%
Fair value of incentive fee	$ 0

Represents the percentage of return earned by entity on achieving specified percentage of internal rate of return on invested equity.

No definition available.

Name:	stag_PercentageOfReturnEarnedByEntityOnAchievingSpecifiedInternalRateOfReturnOnInvestedEquity
Namespace Prefix:	stag_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant