Summary of Significant Accounting Policies - Cash & Cash Equivalents (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Jan. 31, 2015	Feb. 01, 2014
Accounting Policies [Abstract]
Maximum Term of Original Maturity to Classify an Instrument as Cash Equivalents	3 months
Cash Equivalents, at Carrying Value	$ 1,660us-gaap_CashEquivalentsAtCarryingValue	$ 1,705us-gaap_CashEquivalentsAtCarryingValue
Weighted Average Interest Rate on Cash Equivalents	0.40%	0.50%
Bank Overdrafts	$ 0us-gaap_BankOverdrafts	$ 62us-gaap_BankOverdrafts

This element represents maximum original term to maturity of an instrument to classify as cash or cash equivalent.

No definition available.

Name:	bby_MaximumTermOfOriginalMaturityToClassifyInstrumentAsCashEquivalents
Namespace Prefix:	bby_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the weighted-average interest rate on cash equivalents.

+ References

No definition available.

+ Details

Name:	bby_WeightedAverageInterestRateOnCashEquivalents
Namespace Prefix:	bby_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AccountingPoliciesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying value as of the balance sheet date of payments made in excess of existing cash balances, which will be honored by the bank but reflected as a loan to the entity. Overdrafts generally have a very short time frame for correction or repayment and are therefore more similar to short-term bank financing than trade financing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Current Liabilities

-URI http://asc.fasb.org/extlink&oid=6509677

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.20)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 10

-Section 45

-Paragraph 10

-URI http://asc.fasb.org/extlink&oid=28361426&loc=d3e1243-112600

+ Details

Name:	us-gaap_BankOverdrafts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.1)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_CashEquivalentsAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant