Acquisition of facilities (Details) $ in Millions	3 Months Ended
Oct. 28, 2016 USD ($) store
Acquisition of facilities
Number of stores acquired	42
Number of stores closing	40
Selling, general and administrative expenses \| $	$ 11.0

The aggregate total costs related to an asset purchase. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

No definition available.

Name:	dg_SellingGeneralAndAdministrativeExpenseRelatedToAssetPurchase
Namespace Prefix:	dg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration