Exit and disposal activities (Details) $ in Millions		9 Months Ended
	Oct. 24, 2017 store	May 31, 2018 USD ($)
Store Optimization Program
Restructuring Reserve Disclosures [Abstract]
Number of stores expected to close | store	600
Duration of restructuring plan	18 months
Expected cost		$ 450
Restructuring Reserve [Roll Forward]
Beginning Balance		0
Costs		24
Payments		(8)
Other - non cash		30
Ending Balance		46
Store Optimization Program | Lease obligations and other real estate costs
Restructuring Reserve Disclosures [Abstract]
Expected cost		270
Restructuring Reserve [Roll Forward]
Beginning Balance		0
Costs		2
Payments		0
Other - non cash		30
Ending Balance		32
Store Optimization Program | Severance and other business transition and exit costs
Restructuring Reserve Disclosures [Abstract]
Expected cost		180
Restructuring Reserve [Roll Forward]
Beginning Balance		0
Costs		22
Payments		(8)
Other - non cash		0
Ending Balance		14
Cost Transformation Program
Restructuring Reserve [Roll Forward]
Beginning Balance		600
Payments		(180)
Other - non cash		19
Currency translation adjustments		(1)
Ending Balance		438
Cost Transformation Program | Real estate costs
Restructuring Reserve [Roll Forward]
Beginning Balance		521
Payments		(112)
Other - non cash		20
Currency translation adjustments		0
Ending Balance		429
Cost Transformation Program | Severance and other business transition and exit costs
Restructuring Reserve [Roll Forward]
Beginning Balance		79
Payments		(68)
Other - non cash		(1)
Currency translation adjustments		(1)
Ending Balance		$ 9