Earnings per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	May 05, 2012	Apr. 30, 2011
Numerator
Net earnings from continuing operations	$ 161	$ 293
Net (earnings) from continuing operations attributable to noncontrolling interests	0	(38)
Net earnings from continuing operations attributable to Best Buy Co., Inc., basic	161	255
Adjustment for assumed dilution:
Interest on convertible debentures, net of tax (in dollars)	0	1
Net earnings attributable to Best Buy Co., Inc., diluted (in dollars)	$ 161	$ 256
Denominator
Weighted-average common shares outstanding (in shares)	342.2	391.1
Effect of potentially dilutive securities:
Shares from assumed conversion of convertible debentures (in shares)	0	8.8
Stock options and other (in shares)	0.6	0.8
Weighted-average common shares outstanding, assuming dilution (in shares)	342.8	400.7
Net earnings per share from continuing operations attributable to Best Buy Co., Inc.
Basic (in dollars per share)	$ 0.47	$ 0.65
Diluted (in dollars per share)	$ 0.47	$ 0.64
Antidilutive securities excluded from computation of earnings per share	31.7	29.3