Discontinued Operations (Details 2) In Millions, unless otherwise specified	3 Months Ended									11 Months Ended		12 Months Ended									12 Months Ended		12 Months Ended
	Jan. 31, 2015 USD ($)	Nov. 01, 2014 USD ($)	Aug. 02, 2014 USD ($)	Aug. 02, 2014 GBP (£)	May 03, 2014 USD ($)	Feb. 01, 2014 USD ($)	Nov. 02, 2013 USD ($)	Aug. 03, 2013 USD ($)	May 04, 2013 USD ($)	Feb. 02, 2013 USD ($)		Jan. 31, 2015 USD ($)		Jan. 31, 2015 GBP (£)	Feb. 01, 2014 USD ($)		Feb. 01, 2014 Best Buy Europe [Member] USD ($)	Feb. 01, 2014 Best Buy Europe fixed line of Business in Switzerland [Member] USD ($)	Feb. 01, 2014 Domestic [Member] mindSHIFT [Domain] USD ($)	Feb. 28, 2009 Best Buy Europe [Member]	Feb. 01, 2014 Discontinued Operations [Member] USD ($)	Jan. 31, 2015 Discontinued Operations [Member] Not Designated as Hedging Instrument [Member] GBP (£)	Jan. 31, 2015 Operating Expense [Member] Discontinued Operations [Member] USD ($)	Feb. 01, 2014 China [Member] USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of Long-Lived Assets to be Disposed of																					$ 175
Goodwill impairments										614		0			0									208
Business Acquisition, Percentage of Voting Interests Acquired																				50.00%
Proceeds from Divestiture of Businesses			526	341
Dollar Amount of Shares Received from Divestiture of Business			123	80
Future Cash Consideration from Divestiture of Business, Due within One Year			39	25
Future Cash Consideration from Divestiture of Business, Due within Two Years			39	25
Interest Rate on Future Cash Consideration from Divestiture of Business			2.50%	2.50%
Revenue										6,834		1,564			4,615
Restructuring charges										34	[1]	18	[1]		110	[1]
Gain (loss) from discontinued operations before income tax benefit										(187)	[2]	(12)	[2]		(235)	[2]
Income tax benefit										30	[3]	0	[3]		31	[3]
Gain on sale of discontinued operations										0	[4]	1	[4]		32	[4]	24	28	(18)
Equity in loss of affiliates										(4)		0			0
Net gain (loss) from discontinued operations including noncontrolling interests	(4)	(9)	10		(8)	(6)	4	15	(185)	(161)		(11)			(172)
Net (earnings) loss from discontinued operations attributable to noncontrolling interests										(21)		(2)			9
Net gain (loss) from discontinued operations attributable to Best Buy Co., Inc.										(182)		(13)			(163)
Income Tax Expense (Benefit), Intraperiod Tax Allocation												27
Other Tax Expense (Benefit)												15
Derivative, Notional Amount	554					157						554			157							455
Net Proceeds from Divestiture of Businesses														471
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments												$ (12)			$ (5)								$ 2

[1] See Note 4, Restructuring Charges, for further discussion of the restructuring charges associated with discontinued operations.

[2] Includes the $175 million impairment to write down the book value of our investment in Best Buy Europe to fair value in fiscal 2014 and the $208 million goodwill impairment related to our Five Star reporting unit in fiscal 2013 (11-month).

[3] Income tax benefit for fiscal 2014 includes a $27 million benefit related to a tax allocation between continuing and discontinued operations and a $15 million benefit related to the impairment of our investment in Best Buy Europe. The fiscal 2014 effective tax rate for discontinued operations differs from the statutory tax rate primarily due to the previously mentioned tax allocation, sale of mindSHIFT, restructuring charges and the impairment of our investment in Best Buy Europe. The sale of mindSHIFT, restructuring charges and impairment generally included no related tax benefit. The deferred tax assets related to the sale of mindSHIFT and restructuring charges generally resulted in an increase in the valuation allowance in an equal amount, of which the investment impairment is not tax deductible.

[4] Gain in fiscal 2014 is primarily comprised of the following: $28 million gain (with no tax impact) from sale of Best Buy Europe fixed-line business in Switzerland in the first quarter; $24 million gain (with no tax impact) from the sale of Best Buy Europe in the second quarter; and loss of $18 million from sale of mindSHIFT in the fourth quarter.