Earnings per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Aug. 04, 2012	Jul. 30, 2011	Aug. 04, 2012	Jul. 30, 2011
Numerator
Net (loss) earnings from continuing operations	$ (7)	$ 148	$ 154	$ 441
Net loss (earnings) from continuing operations attributable to noncontrolling interests	19	2	19	(36)
Net earnings from continuing operations attributable to Best Buy Co., Inc., basic	12	150	173	405
Adjustment for assumed dilution:
Interest on convertible debentures, net of tax (in dollars)	0	2	0	3
Net earnings attributable to Best Buy Co., Inc., diluted (in dollars)	$ 12	$ 152	$ 173	$ 408
Denominator
Weighted-average common shares outstanding (in shares)	338.2	376.0	340.3	383.6
Effect of potentially dilutive securities:
Shares from assumed conversion of convertible debentures (in shares)	0	8.8	0	8.8
Stock options and other (in shares)	0.4	0.8	0.7	0.9
Weighted-average common shares outstanding, assuming dilution (in shares)	338.6	385.6	341.0	393.3
Net earnings per share from continuing operations attributable to Best Buy Co., Inc.
Basic (in dollars per share)	$ 0.04	$ 0.40	$ 0.51	$ 1.06
Diluted (in dollars per share)	$ 0.04	$ 0.39	$ 0.51	$ 1.04
Antidilutive securities excluded from computation of earnings per share	29.7	29.7	29.3	29.6