Restructuring Charges Composition of Restructuring Charges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Aug. 04, 2018	Jul. 29, 2017	Aug. 04, 2018	Jul. 29, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 17	$ 2	$ 47	$ 2
Best Buy Mobile
Restructuring Cost and Reserve [Line Items]
Restructuring charges	17	$ 0	47	$ 0
Restructuring and Related Cost, Cost Incurred to Date	56		56
Best Buy Mobile | Property and equipment impairments
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0		0
Restructuring and Related Cost, Cost Incurred to Date	1		1
Best Buy Mobile | Termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges	3		2
Restructuring and Related Cost, Cost Incurred to Date	6		6
Best Buy Mobile | Facility closure and other costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	20		49
Restructuring and Related Cost, Cost Incurred to Date	$ 49		$ 49