Fair Value Measurements (Details 2) (USD $) In Millions	3 Months Ended
May 28, 2011	May 29, 2010	May 28, 2011 Student loan bonds	May 29, 2010 Student loan bonds	May 28, 2011 Municipal revenue bonds	Feb. 26, 2011 Municipal revenue bonds	May 29, 2010 Municipal revenue bonds	Feb. 27, 2010 Municipal revenue bonds
Fair Value, Assets Measured On Recurring Basis, Unobservable Input Reconciliation.
Balance at the beginning of the period	$ 110	$ 280	$ 108	$ 261	$ 2	$ 2	$ 19	$ 19
Changes in unrealized losses included in other comprehensive income	3	(5)	3	(5)
Sales	(14)	(41)	(14)	(41)
Interest received		(1)		(1)
Balance at the end of the period	$ 99	$ 233	$ 97	$ 214	$ 2	$ 2	$ 19	$ 19

Sales that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

Name:	bby_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales
Namespace Prefix:	bby
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This element represents the net interest received, arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3).

+ Details

Name:	bby_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisInterestReceivedNet
Namespace Prefix:	bby
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ Details

Name:	us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 157
-Paragraph 32
-Subparagraph c(1)

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncome
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 157
-Paragraph 32
-Subparagraph c

+ Details

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Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant