Quarterly Financial Information (Unaudited) Quarterly Financial Information (Unaudited) (Details)		3 Months Ended																	12 Months Ended
		Feb. 03, 2018 USD ($) $ / shares		Oct. 28, 2017 USD ($) $ / shares		Jul. 29, 2017 USD ($) $ / shares		Apr. 29, 2017 USD ($) $ / shares		Jan. 28, 2017 USD ($) $ / shares		Oct. 29, 2016 USD ($) $ / shares		Jul. 30, 2016 USD ($) $ / shares		Apr. 30, 2016 USD ($) $ / shares		May 02, 2015 store	Feb. 03, 2018 USD ($) $ / shares		Jan. 28, 2017 USD ($) $ / shares		Jan. 30, 2016 USD ($) $ / shares
Quarterly Financial Information [Line Items]
Net earnings from continuing operations		$ 364,000,000	[1]	$ 238,000,000	[1]	$ 209,000,000	[1]	$ 188,000,000	[1]	$ 607,000,000		$ 192,000,000		$ 182,000,000		$ 226,000,000			$ 999,000,000	[1]	$ 1,207,000,000		$ 807,000,000
Gain from discontinued operations (Note 2), net of tax expense of $0, $7 and $1, respectively		0		1,000,000		0		0		0		2,000,000		16,000,000		3,000,000			1,000,000		21,000,000		90,000,000
Revenue		$ 15,363,000,000		$ 9,320,000,000		$ 8,940,000,000		$ 8,528,000,000		$ 13,482,000,000		$ 8,945,000,000		$ 8,533,000,000		$ 8,443,000,000			$ 42,151,000,000		$ 39,403,000,000		39,528,000,000
Comparable sales % change(1)	[2]	9.00%		4.40%		5.40%		1.60%		(0.70%)		1.80%		0.80%		(0.10%)			5.60%		0.30%
Gross profit		$ 3,421,000,000		$ 2,280,000,000		$ 2,153,000,000		$ 2,022,000,000		$ 3,030,000,000		$ 2,203,000,000		$ 2,062,000,000		$ 2,145,000,000			$ 9,876,000,000		$ 9,440,000,000		9,191,000,000
Operating income(2)		872,000,000	[3]	350,000,000	[3]	321,000,000	[3]	300,000,000	[3]	881,000,000	[4]	312,000,000	[4]	289,000,000	[4]	372,000,000	[4]		1,843,000,000	[3]	1,854,000,000	[4]	1,375,000,000
Net earnings		$ 364,000,000		$ 239,000,000		$ 209,000,000		$ 188,000,000		$ 607,000,000		$ 194,000,000		$ 198,000,000		$ 229,000,000			$ 1,000,000,000		$ 1,228,000,000		$ 897,000,000
Diluted earnings (loss) per share
Continuing operations | $ / shares		$ 1.23		$ 0.78		$ 0.67		$ 0.60		$ 1.91		$ 0.60		$ 0.56		$ 0.69			$ 3.26		$ 3.74		$ 2.30
Discontinued operations | $ / shares		0.00		0.00		0.00		0.00		0.00		0.01		0.05		0.01			0.00		0.07		0.26
Diluted (in dollars per share) | $ / shares		$ 1.23	[5]	$ 0.78	[5]	$ 0.67	[5]	$ 0.60	[5]	$ 1.91	[5]	$ 0.61	[5]	$ 0.61	[5]	$ 0.70	[5]		$ 3.26	[5]	$ 3.81	[5]	$ 2.56
Months until inclusion in comparable store sales																			14 months
Days Until Excluded From Comparable Sales																			14 days
Restructuring charges		$ 10,000,000		$ (2,000,000)		$ 2,000,000		$ 0		$ 9,000,000		$ 1,000,000		$ 0		$ 29,000,000			$ 10,000,000		$ 39,000,000		$ 201,000,000
One-time bonus		80,000,000
One-time contribution		20,000,000
Tax Reform																			283,000,000
Tax Cuts and Jobs Act, Incomplete Accounting, Transition Tax for Accumulated Foreign Earnings, Provisional Income Tax Expense (Benefit)																			209,000,000
Tax Cuts and Jobs Act, Incomplete Accounting, Change in Tax Rate, Deferred Tax Asset (Liability), Provisional Income Tax Expense (Benefit)																			74,000,000
Proceeds from Legal Settlements																183,000,000					183,000,000
Proceeds from Legal Settlements, net of related legal fees and costs																$ 161,000,000					161,000,000
Continuing Operations [Member]
Diluted earnings (loss) per share
Restructuring charges																			$ 10,000,000		39,000,000
Restructuring Program Canadian Brand Consolidation [Member]
Diluted earnings (loss) per share
Number of Stores to be Closed | store																		66
Number of Future Shop stores converted to Best Buy stores | store																		65
Adjustment for Tax Act [Member]
Diluted earnings (loss) per share
Tax Reform		283,000,000																			$ 0		$ 0
Tax Cuts and Jobs Act, Incomplete Accounting, Transition Tax for Accumulated Foreign Earnings, Provisional Income Tax Expense (Benefit)		209,000,000
Tax Cuts and Jobs Act, Incomplete Accounting, Change in Tax Rate, Deferred Tax Asset (Liability), Provisional Income Tax Expense (Benefit)		$ 74,000,000

[1] Includes $283 million of charges resulting from the Tax Act for the fiscal fourth quarter and 12 months 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.

[2] 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. The Canadian brand consolidation, which included the permanent closure of 66 Future Shop stores, the conversion of 65 Future Shop stores to Best Buy stores and the elimination of the Future Shop website, had a material impact on a year-over-year basis on the remaining Canadian retail stores and the website. As such, from the first quarter of fiscal 2016 through the third quarter of fiscal 2017, all Canadian store and website revenue was removed from the comparable sales base and the International segment no longer had a comparable metric. Therefore, Consolidated comparable sales equaled the Domestic segment comparable sales. Beginning in the fourth quarter of fiscal 2017, we resumed reporting International comparable sales as revenue in the International segment was once again deemed to be comparable and, as such, Consolidated comparable sales are once again equal to the aggregation of Domestic and International comparable sales.

[3] Includes $0 million, $2 million, $(2) million and $10 million of restructuring charges (benefit) recorded in the fiscal first, second, third and fourth quarters, respectively, and $10 million for the 12 months 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 12 months ended February 3, 2018.

[4] Includes $29 million, $0 million, $1 million and $9 million of restructuring charges recorded in the fiscal first, second, third and fourth quarters, respectively, and $39 million for the 12 months ended January 28, 2017, related to measures we took to restructure our businesses. Also, includes $161 million of CRT litigation settlements, net of related legal fees and costs, recorded in the fiscal first quarter and in the 12 months ended January 28, 2017, related to products purchased and sold in prior fiscal years.

[5] 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.