Shareholders' Equity (Details 2) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Jan. 30, 2016	Oct. 31, 2015	Aug. 01, 2015	May. 02, 2015	Jan. 31, 2015	Nov. 01, 2014	Aug. 02, 2014	May. 03, 2014	Jan. 30, 2016	Jan. 31, 2015	Feb. 01, 2014	Feb. 02, 2013	Jun. 30, 2011
Outstanding Options to Purchase Common Stock [Line Items]
Net cash proceeds from the exercise of stock options (in dollars)									$ 40	$ 42	$ 158
Weighted-average grant-date fair value of stock options granted (in dollars per share)									$ 11.59	$ 9.09	$ 7.77
Exercisable stock options (in shares)	11,668,000								11,668,000
Percentage of exercisable stock options (as a percent)	100.00%								100.00%
Exercisable stock options, weighted-average price (in dollars per share)	$ 37.09								$ 37.09
Unexercisable stock options (in shares)	2,500,000.0								2,500,000.0
Percentage of unexercisable stock options (as a percent)	100.00%								100.00%
Unexercisable stock options, weighted-average price (in dollars per share)	$ 33.87								$ 33.87
Total outstanding stock options (in shares)	14,242,000				17,342,000				14,242,000	17,342,000
Percentage of outstanding stock options (as a percent)	100.00%								100.00%
Outstanding stock options, weighted-average price (in dollars per share)	$ 36.51				$ 36.81				$ 36.51	$ 36.81
Adjustment for assumed dilution:
Net earnings from continuing operations attributable to Best Buy Co., Inc., diluted									$ 807	$ 1,246	$ 695
Denominator [Abstract]
Weighted-average common shares outstanding (in shares)									346,500,000	349,500,000	342,100,000
Effect of Potentially Dilutive Securities [Abstract]
Stock options and other (in shares)									4,200,000	4,100,000	5,500,000
Weighted-average common shares outstanding, assuming dilution (in shares)									350,700,000	353,600,000	347,600,000
Earnings per share attributable to Best Buy Co., Inc.
Basic (in dollars per share)									$ 2.33	$ 3.57	$ 2.03
Diluted (in dollars per share)	$ 1.39	$ 0.37	$ 0.46	$ 0.10	$ 1.47	$ 0.33	$ 0.39	$ 1.33	$ 2.30	$ 3.53	$ 2.00
Share repurchases authorized (in shares)													$ 5,000
Open Market Repurchases [Abstract]
Stock Repurchased and Retired During Period, Value									$ 120
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation	$ 271				$ 382				271	$ 382	$ 485	$ 113
Unrealized gains (losses) on available-for-sale investments	0				0				0	0	7	(1)
Total	$ 271				$ 382				271	382	492	$ 112
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value									14	13	39
Actual income tax benefit realized from stock option exercises (in dollars)									$ 5	$ 5	$ 13
In-the-money [Member]
Outstanding Options to Purchase Common Stock [Line Items]
Exercisable stock options (in shares)	4,200,000.0								4,200,000.0
Percentage of exercisable stock options (as a percent)	36.00%								36.00%
Exercisable stock options, weighted-average price (in dollars per share)	$ 24.73								$ 24.73
Unexercisable stock options (in shares)	1,300,000.0								1,300,000.0
Percentage of unexercisable stock options (as a percent)	52.00%								52.00%
Unexercisable stock options, weighted-average price (in dollars per share)	$ 27.45								$ 27.45
Total outstanding stock options (in shares)	5,500,000.0								5,500,000.0
Percentage of outstanding stock options (as a percent)	39.00%								39.00%
Outstanding stock options, weighted-average price (in dollars per share)	$ 25.37								$ 25.37
Out-of-the-money [Member]
Outstanding Options to Purchase Common Stock [Line Items]
Exercisable stock options (in shares)	7,500,000.0								7,500,000.0
Percentage of exercisable stock options (as a percent)	64.00%								64.00%
Exercisable stock options, weighted-average price (in dollars per share)	$ 44.15								$ 44.15
Unexercisable stock options (in shares)	1,200,000.0								1,200,000.0
Percentage of unexercisable stock options (as a percent)	48.00%								48.00%
Unexercisable stock options, weighted-average price (in dollars per share)	$ 40.51								$ 40.51
Total outstanding stock options (in shares)	8,700,000.0								8,700,000.0
Percentage of outstanding stock options (as a percent)	61.00%								61.00%
Outstanding stock options, weighted-average price (in dollars per share)	$ 43.62								$ 43.62
June 2011 share repurchase program [Member}
Outstanding Options to Purchase Common Stock [Line Items]
Amounting remaining for additional share repurchases	$ 3,000								$ 3,000
Open Market Repurchases [Abstract]
Total number of shares repurchased									32,800,000
Stock Repurchased and Retired During Period, Value									$ 1,000
Open market [Domain]
Open Market Repurchases [Abstract]
Total number of shares repurchased									28,400,000
January 2016 ASR [Domain]
Open Market Repurchases [Abstract]
Total number of shares repurchased									4,400,000
Market-based [Member]
Outstanding Options to Purchase Common Stock [Line Items]
Unrecognized compensation (in dollars)	$ 19								$ 19
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Weighted-average period over which compensation expense is expected to be recognized (in years)									1 year 10 months
Employee Stock [Member]
Outstanding Options to Purchase Common Stock [Line Items]
Issuance of common stock under employee stock purchase plan (in shares)									200,000	300,000	600,000
Open market [Domain] | June 2011 share repurchase program [Member}
Open Market Repurchases [Abstract]
Stock Repurchased and Retired During Period, Value									$ 880