Debt (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 27, 2019	Jan. 28, 2018
Debt Instrument [Line Items]
Unamortized debt discount and issuance costs	$ (12)	$ (15)
Net carrying amount	$ 1,988	1,985
2.20% Notes Due 2021
Debt Instrument [Line Items]
Expected Remaining Term (years)	2 years 7 months 24 days
Effective Interest Rate (as percent)	2.38%
Gross carrying amount	$ 1,000	1,000
3.20% Notes Due 2026
Debt Instrument [Line Items]
Expected Remaining Term (years)	7 years 7 months 24 days
Effective Interest Rate (as percent)	3.31%
Gross carrying amount	$ 1,000	$ 1,000