Income Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended			12 Months Ended			14 Months Ended
	Jan. 27, 2019	Oct. 28, 2018	Jan. 28, 2018	Jan. 27, 2019	Jan. 28, 2018	Jan. 29, 2017	Jan. 27, 2019
Income Tax Disclosure [Abstract]
Tax expense computed at federal statutory rate				$ 818	$ 1,084	$ 667
Expense (benefit) resulting from:
State income taxes, net of federal tax effect				23	10	4
Foreign tax rate differential				(412)	(545)	(315)
Stock-based compensation				(191)	(181)	(70)
Tax Cuts and Jobs Act of 2017	$ (230)	$ (138)	$ (133)	(368)	(133)	0	$ (501)
U.S. federal R&D tax credit				(141)	(87)	(52)
Other				26	1	5
Income tax expense (benefit)				$ (245)	$ 149	$ 239