Document and Entity Information (USD $) In Billions, except Share data, unless otherwise specified	12 Months Ended
	Jan. 31, 2015	Mar. 23, 2015	Aug. 03, 2013
Document and Entity Information [Abstract}
Entity Registrant Name	BEST BUY CO INC
Current Fiscal Year End Date	--01-31
Entity Voluntary Filers	No
Document Fiscal Year Focus	2015
Amendment Flag	false
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	Yes
Entity Common Stock, Shares Outstanding		352,185,626
Entity Public Float			$ 6.4
Document Fiscal Period Focus	FY
Document Type	10-K
Entity Central Index Key	0000764478
Document Period End Date	Jan. 31, 2015
Entity Filer Category	Large Accelerated Filer