Commitments and Contingencies (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2013
Completion Guarantees
Openings and acquisitions, Total Costs	$ 2,281,145
Openings And Acquisitions, Percent Completed	96.00%
Under construction, Total Costs	666,683
Under construction, Percent Completed	25.00%
Total real estate, Total Costs	$ 2,947,828
Total Real Estate, Percent Completed	80.00%