Shareholders' Equity (Details 2) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended				3 Months Ended								11 Months Ended		12 Months Ended
	Jan. 31, 2012	Jun. 30, 2011	Jan. 31, 2011	Jun. 30, 2007	Feb. 02, 2013	Nov. 03, 2012	Aug. 04, 2012	May 05, 2012	Mar. 03, 2012	Nov. 26, 2011	Aug. 27, 2011	May 28, 2011	Feb. 02, 2013	Jan. 28, 2012	Mar. 03, 2012	Feb. 26, 2011
Outstanding Options to Purchase Common Stock [Line Items]
Net cash proceeds from the exercise of stock options (in dollars)													$ 1		$ 27	$ 134
Weighted-average grant-date fair value of stock options granted (in dollars per share)													$ 5.11		$ 7.94	$ 11.97
Exercisable stock options (in shares)					22,600,000								22,600,000
Percentage of exercisable stock options (as a percent)					100.00%								100.00%
Exercisable stock options, weighted-average price (in dollars per share)					$ 39.98								$ 39.98
Unexercisable stock options (in shares)					7,400,000								7,400,000
Percentage of unexercisable stock options (as a percent)					100.00%								100.00%
Unexercisable stock options, weighted-average price (in dollars per share)					$ 27.55								$ 27.55
Total outstanding stock options (in shares)					30,000,000				35,801,000				30,000,000		35,801,000
Percentage of outstanding stock options (as a percent)					100.00%								100.00%
Outstanding stock options, weighted-average price (in dollars per share)					$ 36.93				$ 38.08				$ 36.93		$ 38.08
Numerator [Abstract]
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	(19)		15		(377)	(5)	(7)	161	(324)	258	197	199	(421)	118	330	1,554
Net (earnings) from continuing operations attributable to noncontrolling interests													(22)	(1,378)	(1,387)	(127)
Net (loss) earnings from continuing operations attributable to Best Buy Co., Inc., basic													(443)		(1,057)	1,427
Adjustment for assumed dilution:
Interest on convertible debentures due in 2022, net of tax													0		0	6
Net earnings from continuing operations attributable to Best Buy Co., Inc., diluted													(443)		(1,057)	1,433
Denominator [Abstract]
Weighted-average common shares outstanding (in shares)													338,600,000	372,500,000	366,300,000	406,100,000
Effect of Potentially Dilutive Securities [Abstract]
Shares from assumed conversion of convertible debentures (in shares)													0		0	8,800,000
Stock options and other (in shares)													0		0	1,600,000
Weighted-average common shares outstanding, assuming dilution (in shares)													338,600,000	372,500,000	366,300,000	416,500,000
Earnings per share attributable to Best Buy Co., Inc.
Basic (in dollars per share)													$ (1.31)	$ (3.38)	$ (2.89)	$ 3.51
Diluted (in dollars per share)					$ (1.21)	$ (0.04)	$ 0.04	$ 0.47	$ (4.73)	$ 0.62	$ 0.52	$ 0.41	$ (1.31)	$ (3.38)	$ (2.89)	$ 3.44
Share repurchases authorized (in shares)		5,000		5,500
Open Market Repurchases [Abstract]
Comprehensive income (loss) attributable to Best Buy Co., Inc. shareholders													(430)		(1,314)	1,410
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation					113				93				113		93
Unrealized gains (losses) on available-for-sale investments					(1)				(3)				(1)		(3)
Total					112				90				112		90
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value													0		6	52
Actual income tax benefit realized from stock option exercises (in dollars)															2	19
In-the-money [Member]
Outstanding Options to Purchase Common Stock [Line Items]
Exercisable stock options (in shares)					100,000								100,000
Percentage of exercisable stock options (as a percent)					0.00%								0.00%
Exercisable stock options, weighted-average price (in dollars per share)					$ 18.02								$ 18.02
Unexercisable stock options (in shares)					2,000,000								2,000,000
Percentage of unexercisable stock options (as a percent)					27.00%								27.00%
Unexercisable stock options, weighted-average price (in dollars per share)					$ 15.78								$ 15.78
Total outstanding stock options (in shares)					2,100,000								2,100,000
Percentage of outstanding stock options (as a percent)					7.00%								7.00%
Outstanding stock options, weighted-average price (in dollars per share)					$ 15.97								$ 15.97
Out-of-the-money [Member]
Outstanding Options to Purchase Common Stock [Line Items]
Exercisable stock options (in shares)					22,500,000								22,500,000
Percentage of exercisable stock options (as a percent)					100.00%								100.00%
Exercisable stock options, weighted-average price (in dollars per share)					$ 40.15								$ 40.15
Unexercisable stock options (in shares)					5,400,000								5,400,000
Percentage of unexercisable stock options (as a percent)					73.00%								73.00%
Unexercisable stock options, weighted-average price (in dollars per share)					$ 31.55								$ 31.55
Total outstanding stock options (in shares)					27,900,000								27,900,000
Percentage of outstanding stock options (as a percent)					93.00%								93.00%
Outstanding stock options, weighted-average price (in dollars per share)					$ 38.46								$ 38.46
June 2011 share repurchase program [Member}
Outstanding Options to Purchase Common Stock [Line Items]
Amounting remaining for additional share repurchases													3,989
Open Market Repurchases [Abstract]
Total number of shares repurchased													6,300,000		34,500,000	0
Total cost of shares repurchased													122		889	0
June 2007 share repurchase program [Member]
Open Market Repurchases [Abstract]
Total number of shares repurchased													0		20,100,000	32,600,000
Total cost of shares repurchased													0		611	1,193
Market-based [Member]
Outstanding Options to Purchase Common Stock [Line Items]
Unrecognized compensation (in dollars)					12								12
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Weighted-average period over which compensation expense is expected to be recognized (in years)													2 years 8 months 4 days
Employee Stock [Member]
Outstanding Options to Purchase Common Stock [Line Items]
Issuance of common stock under employee stock purchase plan (in shares)													1,000,000		1,000,000	1,000,000
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Weighted-average fair value of shares purchased (in dollars per share)													$ 5.44		$ 6.76	$ 9.54
Performance-based [Member]
Outstanding Options to Purchase Common Stock [Line Items]
Unrecognized compensation (in dollars)					$ 0								$ 0