Restructuring Charges Composition of Restructuring Charges (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Feb. 02, 2019	Nov. 03, 2018	Aug. 04, 2018	May 05, 2018	Feb. 03, 2018	Oct. 28, 2017	Jul. 29, 2017	Apr. 29, 2017	Feb. 02, 2019	Feb. 03, 2018	Jan. 28, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 1	$ 0	$ 17	$ 30	$ 10	$ 2	$ 2	$ 0	$ 46	$ 10	$ 39
Best Buy Mobile
Restructuring Cost and Reserve [Line Items]
Restructuring charges									47	9	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	1
Restructuring and Related Cost, Cost Incurred to Date	1								1
Best Buy Mobile | Employee termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges									2	8
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									49	0
Restructuring and Related Cost, Cost Incurred to Date	49								49
Renew Blue Phase 2
Restructuring Cost and Reserve [Line Items]
Restructuring charges									0	0	26
Renew Blue Phase 2 | Property and equipment impairments
Restructuring Cost and Reserve [Line Items]
Restructuring charges											8
Renew Blue Phase 2 | Employee termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges											18
Canadian brand consolidation
Restructuring Cost and Reserve [Line Items]
Restructuring charges									1	2	3
Restructuring and Related Cost, Cost Incurred to Date	200								200
Canadian brand consolidation | Facility closure and other costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges									1	2	3
Renew Blue
Restructuring Cost and Reserve [Line Items]
Restructuring charges									0	3	5
Restructuring and Related Cost, Cost Incurred to Date	$ 371								371
Other
Restructuring Cost and Reserve [Line Items]
Restructuring charges									$ 0	$ 0	$ 5