Quarterly Financial Information (Unaudited) Quarterly Financial Information (Unaudited) (Details) - USD ($)		3 Months Ended																12 Months Ended
		Feb. 02, 2019		Nov. 03, 2018		Aug. 04, 2018		May 05, 2018		Feb. 03, 2018		Oct. 28, 2017		Jul. 29, 2017		Apr. 29, 2017		Feb. 02, 2019		Feb. 03, 2018		Jan. 28, 2017
Quarterly Financial Information Disclosure [Abstract]
Revenue		$ 14,801,000,000		$ 9,590,000,000		$ 9,379,000,000		$ 9,109,000,000		$ 15,363,000,000		$ 9,320,000,000		$ 8,940,000,000		$ 8,528,000,000		$ 42,879,000,000		$ 42,151,000,000		$ 39,403,000,000
Comparable sales growth	[1]	3.00%		4.30%		6.20%		7.10%		9.00%		4.40%		5.40%		1.60%		4.80%		5.60%
Gross profit		$ 3,283,000,000		$ 2,324,000,000		$ 2,229,000,000		$ 2,125,000,000		$ 3,421,000,000		$ 2,280,000,000		$ 2,153,000,000		$ 2,022,000,000		$ 9,961,000,000		$ 9,876,000,000		9,440,000,000
Operating income		978,000,000	[2]	322,000,000	[2]	335,000,000	[2]	265,000,000	[2]	872,000,000	[3]	350,000,000	[3]	321,000,000	[3]	300,000,000	[3]	1,900,000,000	[2]	1,843,000,000	[3]	1,854,000,000
Net earnings from continuing operations										364,000,000	[4]	238,000,000	[4]	209,000,000	[4]	188,000,000	[4]	1,464,000,000		999,000,000	[4]	1,207,000,000
Gain from discontinued operations										0		1,000,000		0		0		0		1,000,000		21,000,000
Net earnings		$ 735,000,000	[5]	$ 277,000,000	[5]	$ 244,000,000	[5]	$ 208,000,000	[5]	$ 364,000,000		$ 239,000,000		$ 209,000,000		$ 188,000,000		$ 1,464,000,000	[5]	$ 1,000,000,000		$ 1,228,000,000
Diluted earnings per share		$ 2.69	[6]	$ 0.99	[6]	$ 0.86	[6]	$ 0.72	[6]	$ 1.23	[6]	$ 0.78	[6]	$ 0.67	[6]	$ 0.60	[6]	$ 5.20	[6]	$ 3.26	[6]	$ 3.81
Months until inclusion in comparable store sales																		14 months
Days until excluded from comparable sales																		14 days
Restructuring charges		$ 1,000,000		$ 0		$ 17,000,000		$ 30,000,000		$ 10,000,000		$ 2,000,000		$ 2,000,000		$ 0		$ 46,000,000		$ 10,000,000		$ 39,000,000
Acquisition-related transaction costs		13,000,000																13,000,000
Non-cash amortization of definite-lived intangible assets		17,000,000		5,000,000				$ 22,000,000
One-time bonus										80,000,000								7,000,000
One-time contribution										20,000,000
Tax Act										283,000,000								(23,000,000)		283,000,000		$ 0
Amounts associated with deemed repatriation tax		$ (2,000,000)		(18,000,000)						209,000,000								(20,000,000)		209,000,000
Amounts related to the revaluation of deferred tax assets and liabilities				$ (5,000,000)						$ 74,000,000								$ (5,000,000)		$ 74,000,000

[1] (1)Our comparable sales calculation compares revenue from stores, websites and call centers operating for at least 14 full months, as well as revenue related to certain other comparable sales channels for a particular period to the corresponding period in the prior year. Relocated stores, as well as remodeled, expanded and downsized stores closed more than 14 days, are excluded from our comparable sales calculation until at least 14 full months after reopening. Acquisitions are included in the comparable sales calculation beginning with the first full quarter following the first anniversary of the date of the acquisition. Comparable sales also exclude the impact of the extra week in fiscal 2018. On March 1, 2018, we announced our intent to close all of our 257 remaining Best Buy Mobile stand-alone stores in the U.S. As a result, all revenue related to these stores has been excluded from the comparable sales calculation beginning in March 2018. On October 1, 2018, we acquired all outstanding shares of GreatCall. Consistent with our comparable sales policy, the results of GreatCall are excluded from our comparable sales calculation for fiscal 2019.

[2] (2)Includes $30 million, $17 million, $0 million and $(1) million of restructuring charges (benefit) recorded in the fiscal first, second, third and fourth quarters of 2019, respectively, and $46 million for the fiscal year ended February 2, 2019, related to measures we took to restructure our businesses. Also includes $13 million of acquisition-related transaction costs in the fiscal third quarter of 2019 and $5 million and $17 million of non-cash amortization of definite-lived intangible assets in the fiscal third and fourth quarters of 2019, respectively, associated with the acquisition of GreatCall. Total non-cash amortization of definite-lived intangible assets for the fiscal year ended February 2, 2019 was $22 million. The fiscal first quarter and year ended February 2, 2019, also includes $7 million related to the one-time bonus for certain employees in response to future tax savings created by the Tax Act.

[3] (5)Includes $0 million, $2 million, $(2) million and $10 million of restructuring charges (benefit) recorded in the fiscal first, second, third and fourth quarters of 2018, respectively, and $10 million for the fiscal year ended February 3, 2018, related to measures we took to restructure our businesses. Also includes $80 million related to a one-time bonus for certain employees and $20 million related to a one-time contribution to the Best Buy Foundation in response to future tax savings created by the Tax Act for the fiscal fourth quarter and year ended February 3, 2018.

[4] (6)Includes $283 million of charges resulting from the Tax Act for the fiscal fourth quarter and year ended February 3, 2018, including $209 million associated with the deemed repatriation tax and $74 million primarily related to the revaluation of deferred tax assets and liabilities.

[5] (3)Includes subsequent adjustments resulting from the Tax Act, including $(18) million, $(2) million and $(20) million associated with the deemed repatriation tax recorded in the fiscal third quarter, fourth quarter and year ended February 2, 2019, respectively, and$(5) million and $(5) million related to the revaluation of deferred tax assets and liabilities recorded in the fiscal third quarter and year ended February 2, 2019, respectively.

[6] (4)The sum of our quarterly diluted earnings per share does not equal our annual diluted earnings per share due to differences in quarterly and annual weighted-average shares outstanding.