Supplementary Financial Information (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended																11 Months Ended		12 Months Ended
	Jan. 31, 2015		Nov. 01, 2014		Aug. 02, 2014		May 03, 2014		Feb. 01, 2014		Nov. 02, 2013		Aug. 03, 2013		May 04, 2013		Feb. 02, 2013		Jan. 31, 2015		Feb. 01, 2014
Quarterly Financial Information [Line Items]
Revenue	$ 14,209		$ 9,032		$ 8,459		$ 8,639		$ 14,025		$ 8,924		$ 8,734		$ 8,928		$ 38,252		$ 40,339		$ 40,611
Comparable store sales % change (as a percent)	2.00%	[1]	2.90%	[1]	(2.20%)	[1]	(1.80%)	[1]	(1.30%)	[1]	0.50%	[1]	(0.60%)	[1]	(1.80%)	[1]			0.50%	[1]	(1.00%)	[1]
Gross profit	3,026		2,076		1,978		1,967		2,828		2,093		2,373		2,105		9,023		9,047		9,399
Operating income (loss)	810	[2]	205	[2]	225	[2]	210	[2]	452	[3]	100	[3]	405	[3]	187	[3]	90		1,450	[2]	1,144	[3]
Net earnings (loss) from continuing operations	524		116		137		469		300		50		233		112		(259)		1,246		695
Gain (loss) from discontinued operations, net of tax	(4)		(9)		10		(8)		(6)		4		15		(185)		(161)		(11)		(172)
Net earnings (loss) including noncontrolling interests	520		107		147		461		294		54		248		(73)		(420)		1,235		523
Net earnings (loss) attributable to Best Buy Co., Inc.	519		107		146		461		293		54		266		(81)		(441)		1,233		532
Diluted earnings (loss) per share
Continuing operations	$ 1.47		$ 0.33		$ 0.39		$ 1.33		$ 0.85		$ 0.15		$ 0.67		$ 0.33		$ (0.76)	[4]	$ 3.53		$ 2.00
Discontinued operations	$ (0.01)	[5]	$ (0.03)	[5]	$ 0.03	[5]	$ (0.02)	[5]	$ (0.02)	[5]	$ 0.01	[5]	$ 0.10	[5]	$ (0.57)	[5]	$ (0.54)		$ (0.04)	[5]	$ (0.47)	[5]
Diluted (in dollars per share)	$ 1.46		$ 0.30		$ 0.42		$ 1.31		$ 0.83		$ 0.16		$ 0.77		$ (0.24)		$ (1.30)		$ 3.49		$ 1.53
Months until inclusion in comparable store sales																			14 months
Days Until Excluded From Comparable Sales																			14 days
Restructuring charges	(7)		5		5		2		113		27		4		5		449		23		259
Goodwill impairments																	614		0		0
Continuing Operations [Member]
Diluted earnings (loss) per share
Restructuring charges																	$ 415		$ 5		$ 149

[1] Our comparable sales calculation compares revenue from stores, websites and call centers operating for at least 14 full months, as well as revenue related to certain other comparable sales channels for a particular period to a corresponding period in the prior year. Relocated, as well as remodeled, expanded and downsized stores closed more than 14 days, are excluded from our comparable store sales calculation until at least 14 full months after reopening. Acquisitions are included in the comparable sales calculation beginning with the first full quarter following the first anniversary of the date of the acquisition. The portion of the calculation of comparable sales attributable to our International segment excludes the effect of fluctuations in foreign currency exchange rates. The calculation of comparable sales excludes the impact of revenue from discontinued operations. Comparable online sales are included in our comparable sales calculation. The method of calculating comparable sales varies across the retail industry. As a result, our method of calculating comparable sales may not be the same as other retailers' methods.

[2] Includes $2 million, $5 million, $5 million and $(7) million of restructuring charges recorded in the fiscal first, second, third and fourth quarters, respectively, and $5 million for the 12 months ended January 31, 2015 related to measures we took to restructure our businesses.

[3] ncludes $5 million, $4 million, $27 million and $113 million of restructuring charges recorded in the fiscal first, second, third and fourth quarters, respectively, and $149 million for the 12 months ended February 1, 2014 related to measures we took to restructure our businesses.

[4] The calculation of diluted loss per share for fiscal 2013 (11-month) does not include potentially dilutive securities because their inclusion would be anti-dilutive (i.e., reduce the net loss per share).

[5] The sum of our quarterly diluted earnings per share does not equal our annual diluted earnings per share due to differences in quarterly and annual weighted-average shares outstanding.