This element represents the aggregate value of failed auctions.

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

The periodic intervals at which the interest rates on the entity's auction-rate securities most commonly reset through an auction process.

+ Details

Name:	bby_AuctionRateSecuritiesRateSettingInterval
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Data Type:	xbrli:stringItemType
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- Definition

The percentage of outstanding shares of a third party that were acquired by the entity.

+ Details

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Namespace Prefix:	bby
Data Type:	us-types:percentItemType
Balance Type:	na
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- Definition

Represents the number of companies from which an entity has been demerged.

+ Details

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Namespace Prefix:	bby
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The high end of the range for the percentage of the entity's loans which are guaranteed.

+ Details

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Namespace Prefix:	bby
Data Type:	us-types:percentItemType
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Period Type:	instant

- Definition

The low end of the range for the percentage of the entity's loans which are guaranteed.

+ Details

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Namespace Prefix:	bby
Data Type:	us-types:percentItemType
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Period Type:	instant

- Definition

The percentage of the securities that are insured by rated bond insurers.

+ Details

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Data Type:	us-types:percentItemType
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- Definition

The number of investments in the entity's portfolio as of the balance sheet date.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage ownership of a former third party in one of the entity's subsidiaries.

+ Details

Name:	bby_PercentageOfOwnership
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Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of the entity's portfolio that is rated A/A by external credit reporting agencies Fitch and Moody's, respectively.

+ Details

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Data Type:	us-types:percentItemType
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- Definition

The percentage of the entity's portfolio that is rated AA/Aa by external credit reporting agencies Fitch and Moody's, respectively.

+ Details

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- Definition

The percentage of the entity's portfolio that is rated AAA/Aaa by external credit reporting agencies Fitch and Moody's, respectively.

+ Details

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Data Type:	us-types:percentItemType
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Period Type:	instant

- Definition

Amount of securities sold, at par, during the period.

+ Details

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Period Type:	duration

- Definition

Amount of securities sold, at par, during the period subsequent to the balance sheet date. This amount ranges from zero to a maximum of the amount of ARS outstanding at the balance sheet date.

+ Details

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- Definition

The weighted average interest rate of securities.

+ Details

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Period Type:	instant

- Definition

Accumulated appreciation or loss, net of tax, in value of the total of unsold securities at the end of an accounting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 130
-Paragraph 26

+ Details

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- Definition

The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 21
-Paragraph 16, 20

+ Details

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- Definition

When presenting a range of maturity dates, the latest date when the outstanding debt instruments are required to be repaid. May be presented in a variety of ways (for example: year only, month and year, day, month and year, and number of years).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 22
-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 129
-Paragraph 2, 4

+ Details

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- Definition

When presenting a range of maturity dates, the earliest date when the outstanding debt instruments are required to be repaid. May be presented in a variety of ways (for example: year only, month and year, day, month and year, and number of years).

+ References

+ Details

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Period Type:	duration

- Definition

Sum of the carrying amounts as of the balance sheet date of current and noncurrent investments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 1
-Subparagraph h
-Article 7

+ Details

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- Definition

The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle).

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

Gross appreciation or the gross loss in value of the total of unsold available-for-sale securities during the period being reported (except when designated as a fair value hedge).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 130
-Paragraph 24
-Subparagraph b

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 13

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph 38
-Subparagraph c(3)

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 130
-Paragraph 17

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ Details

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- Definition

Investments which are intended to be sold in the short term (usually less than one year or the normal operating cycle, whichever is longer) including trading securities, available-for-sale securities, held-to-maturity securities, and other short-term investments not otherwise listed in the existing taxonomy.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 1
-Subparagraph g
-Article 7

+ Details

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

Investments (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended									3 Months Ended									3 Months Ended										12 Months Ended
	Mar. 31, 2010	May 28, 2011	Feb. 26, 2011	May 29, 2010	Feb. 26, 2011 Money Market Fund	May 29, 2010 Money Market Fund	May 28, 2011 U.S. Treasury bills	Feb. 26, 2011 U.S. Treasury bills	May 29, 2010 U.S. Treasury bills	May 28, 2011 Debt Securities (Auction-Rate Securities)	Feb. 26, 2011 Debt Securities (Auction-Rate Securities)	May 29, 2010 Debt Securities (Auction-Rate Securities)	May 28, 2011 Student loan bonds	Feb. 26, 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	May 28, 2011 Marketable Equity Securities	Feb. 26, 2011 Marketable Equity Securities	May 29, 2010 Marketable Equity Securities	May 28, 2011 Common stock of Talk Talk Telecom Group PLC	Feb. 26, 2011 Common stock of Talk Talk Telecom Group PLC	May 29, 2010 Common stock of Talk Talk Telecom Group PLC	May 28, 2011 Common stock of Carphone Warehouse Group plc	Feb. 26, 2011 Common stock of Carphone Warehouse Group plc	May 29, 2010 Common stock of Carphone Warehouse Group plc	May 29, 2010 Marketable Equity Securities, Other	Mar. 01, 2008 Common stock of The Carphone Warehouse Group PLC	May 28, 2011 Other Investments	Feb. 26, 2011 Other Investments	May 29, 2010 Other Investments
Schedule of Investments
Total short-term investments		$ 20	$ 22	$ 205	$ 2	$ 2	$ 20	$ 20	$ 150			$ 53
Total equity and other investments		318	328	323						99	110	180							145	146	87	62	62	46	83	84	36	5		74	72	56
Interval of auction process										Seven, 28 and 35 days
Securities redeemed										14
Investments in portfolio										20
Aggregate value of failed auctions										101
Securities subsequently sold										2
Investments										99	110	233	97	108	214	2	2	19
Guaranteed or Insured Percentage, Low Range (as a percent)													95.00%
Guaranteed or Insured Percentage, High Range (as a percent)													100.00%
Percentage Insured by Rated Bond Insurers (as a percent)																100.00%
Debt Instrument, Par Value										101	115	243
Weighted Average Interest Rate Percentage (as a percent)										0.68%	0.80%	1.49%
Percentage of Portfolio With Credit Rating AAA/Aaa (as a percent)										83.00%
Percentage of Portfolio With Credit Rating AA/Aa (as a percent)										2.00%
Percentage of Portfolio With Credit Rating A/A (as a percent)										15.00%
Maturity of debt issuances, start (in years)										5 years
Maturity of debt issuances, end (in years)										32 years
Pre-tax unrealized gain (loss) in accumulated other comprehensive income										(2)									85
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax		$ 73	$ 72	$ 19						$ (1)	$ (3)	$ (6)							$ 74	$ 75	$ 25
Percentage of Entity Acquired (as a percent)																													3.00%
Number of companies formed after CPW demerger	2
Percentage ownership of former CPW in Best Buy Europe, included in Carphone Warehouse holding company (as a percent)	50.00%