Quarterly Summary (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended											12 Months Ended						14 Months Ended
	Jan. 27, 2019		Oct. 28, 2018		Jul. 29, 2018	Apr. 29, 2018	Jan. 28, 2018		Oct. 29, 2017	Jul. 30, 2017	Apr. 30, 2017	Jan. 27, 2019		Jan. 28, 2018		Jan. 29, 2017		Jan. 27, 2019
Selected Quarterly Financial Information [Abstract]
Revenue	$ 2,205		$ 3,181		$ 3,123	$ 3,207	$ 2,911		$ 2,636	$ 2,230	$ 1,937	$ 11,716		$ 9,714		$ 6,910
Cost of revenue	998		1,260		1,148	1,139	1,110		1,067	928	787	4,545		3,892		2,847
Gross profit	1,207		1,921		1,975	2,068	1,801	[1]	1,569	1,302	1,150	7,171		5,822		4,063
Net income	$ 567	[2]	$ 1,230	[2]	$ 1,101	$ 1,244	$ 1,118	[1]	$ 838	$ 583	$ 507	$ 4,141		$ 3,047		$ 1,666
Net income per share:
Basic (in USD per share)	$ 0.93	[2]	$ 2.02	[2]	$ 1.81	$ 2.05	$ 1.84	[1]	$ 1.39	$ 0.98	$ 0.86	$ 6.81	[3]	$ 5.09	[3]	$ 3.08	[3]
Diluted (in USD per share)	$ 0.92	[2]	$ 1.97	[2]	$ 1.76	$ 1.98	$ 1.78	[1]	$ 1.33	$ 0.92	$ 0.79	$ 6.63	[4]	$ 4.82	[4]	$ 2.57	[4]
Tax Cuts and Jobs Act of 2017, income tax benefit	$ 230		$ 138				$ 133					$ 368		$ 133		$ 0		$ 501

[1] In the fourth quarter of fiscal year 2018, we recorded a U.S. tax reform provisional net tax benefit of $133 million associated with the one-time transition tax on our historical foreign earnings and the adjustment of deferred tax balances to the lower corporate tax rate. Refer to Note 13 of these Notes to the Consolidated Financial Statements for a discussion regarding the U.S. tax reform.

[2] In the third and fourth quarters of fiscal year 2019, we recorded U.S. tax reform benefits of $138 million and $230 million, respectively, associated with the completion of our accounting for the enactment-date income tax effects of the TCJA. Refer to Note 13 of these Notes to the Consolidated Financial Statements for a discussion regarding the U.S. tax reform.

[3] Calculated as net income divided by basic weighted average shares.

[4] Calculated as net income divided by diluted weighted average shares.