Commitments and contingencies (Details 2) (USD $) In Millions, unless otherwise specified	1 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	1 Months Ended				1 Months Ended
	Jan. 01, 2010 Cynthia Richter, et al. v. Dolgencorp, Inc ("Richter") Employees	Feb. 03, 2012 Cynthia Richter, et al. v. Dolgencorp, Inc ("Richter") Plaintiffs	Apr. 04, 2008 Janet Calvert v. Dolgencorp, Inc ("Calvert") Plaintiffs	Feb. 03, 2012 Janet Calvert v. Dolgencorp, Inc ("Calvert")	Jul. 02, 2010 Shaleka Gross, et al v. Dollar General Corporation Plaintiffs	Oct. 01, 2010 Cynthia Walker, et al. v. Dollar General Corporation, et al. Plaintiffs	May 27, 2011 Winn-Dixie Stores, Inc., et al. v. Dolgencorp, LLC Stores	Feb. 03, 2012 Winn-Dixie Stores, Inc., et al. v. Dolgencorp, LLC	Apr. 29, 2011 Interest rate swap settlement	May 28, 2010 Interest rate swap settlement	Nov. 28, 2008 Interest rate swap settlement
Legal proceedings
Minimum number of current or former Dollar General store managers to whom notice was mailed	28,000
Approximate number of persons who opted into the lawsuit		3,950	2,100
Approximate number of opt-in plaintiffs dismissed		800
Settlement consideration				$ 15.5
Plaintiffs' legal fees				3.25
Aggregate anticipated settlement payments				18.75
Expected reimbursement from Employment Practices Liability Insurance (EPLI)				15.9
Insurance coverage under Employment Practices Liability Insurance (EPLI)				20
Number of persons who filed lawsuit					3
Approximate number of plaintiffs added to the lawsuit						8
Number of stores co-located with one of the plaintiffs' stores							55
Expected amount sought by plaintiffs								47
Interest rate swap settlement payment									9.85		7.60
Demand for additional settlement amount of interest rate swap										$ 19