Commitments and contingencies (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	9 Months Ended	2 Months Ended	9 Months Ended	1 Months Ended		9 Months Ended	1 Months Ended		1 Months Ended
	Jan. 01, 2010 Cynthia Richter, et al. v. Dolgencorp, Inc ("Richter") employee	Oct. 28, 2011 Cynthia Richter, et al. v. Dolgencorp, Inc ("Richter") plaintiff	Mar. 11, 2008 Janet Calvert v. Dolgencorp, Inc ("Calvert") plaintiff	Oct. 28, 2011 Janet Calvert v. Dolgencorp, Inc ("Calvert")	Jul. 02, 2010 Shaleka Gross, et al v. Dollar General Corporation plaintiff	Oct. 01, 2010 Cynthia Walker, et al. v. Dollar General Corporation, et al. plaintiff defendant	Oct. 28, 2011 Cynthia Walker, et al. v. Dollar General Corporation, et al. day	May 27, 2011 Winn-Dixie Stores, Inc., et al. v. Dolgencorp, LLC store	Oct. 28, 2011 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		3,860
Approximate number of opt-in plaintiffs who filed consent forms			2,100
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
Number of corporate defendants						2
Approximate number of plaintiffs added to the lawsuit						8
Number of plaintiffs dismissed						2
Period of filing of response to any conditional certification motion (in days)							30
Approximate number of stores co-located with one of the plaintiffs' store								70
Estimated amount of damages that may be demanded by plaintiffs'									55
Interest rate swap settlement payment										9.85		7.60
Demand for additional settlement amount of interest rate swap											$ 19