Earnings per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Nov. 26, 2011	Nov. 27, 2010	Nov. 26, 2011	Nov. 27, 2010
Numerator
Net earnings attributable to Best Buy Co., Inc., basic (in dollars)	$ 154	$ 217	$ 467	$ 626
Adjustment for assumed dilution:
Interest on convertible debentures, net of tax (in dollars)	1	2	4	4
Net earnings attributable to Best Buy Co., Inc., diluted (in dollars)	$ 155	$ 219	$ 471	$ 630
Denominator
Weighted-average common shares outstanding (in shares)	359.7	397.1	373.1	410.3
Effect of potentially dilutive securities:
Shares from assumed conversion of convertible debentures (in shares)	8.7	8.8	8.7	8.8
Stock options and other (in shares)	0.4	1.9	0.6	1.6
Weighted-average common shares outstanding, assuming dilution (in shares)	368.8	407.8	382.4	420.7
Earnings per share attributable to Best Buy Co., Inc.
Basic (in dollars per share)	$ 0.43	$ 0.55	$ 1.25	$ 1.53
Diluted (in dollars per share)	$ 0.42	$ 0.54	$ 1.23	$ 1.50
Antidilutive securities excluded from computation of earnings per share	33.8	16.1	29.9	18.6