Stock-Based Compensation - Equity Incentive Plans (Details) shares in Thousands	12 Months Ended
	Jan. 27, 2019 $ / shares shares
Number of Shares
RSUs, PSUs and Market-based PSUs, outstanding, beginning balance (in shares)	22,000
RSUs, PSUs and Market-based PSUs, granted (in shares)	4,000	[1],[2]
RSUs, PSUs and Market-based PSUs, vested (in shares)	(10,000)
RSUs, PSUs and Market-based PSUs, canceled and forfeited (in shares)	0
RSUs, PSUs and Market-based PSUs, outstanding, ending balance (in shares)	16,000
Weighted Average Grant-Date Fair Value
PSUs and Market-based PSUs, weighted average grant date fair value, beginning balance (in USD per share) | $ / shares	$ 66.72
PSUs and Market-based PSUs, weighted average grant date fair value, granted (in USD per share) | $ / shares	258.26
PSUs and Market-based PSUs, weighted average grant date fair value, vested (in USD per share) | $ / shares	52.56
PSUs and Market-based PSUs, weighted average grant date fair value, canceled and forfeited (in USD per share) | $ / shares	0.00
PSUs and Market-based PSUs, weighted average grant date fair value, ending balance (in USD per share) | $ / shares	$ 129.92
Vested and expected to vest, RSUs, PSUs and Market-based PSUs (in shares)	13,000
Vested and expected to vest, RSUs, PSUs and Market-based PSUs, weighted average grant date fair value (in USD per share) | $ / shares	$ 129.44
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of market-based PSUs issuable (in shares)	45
Market-based PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Measurement period	3 years

[1] Includes PSUs that will be issued and eligible to vest based on the corporate financial performance level achieved for fiscal year 2019.

[2] Includes market-based PSUs that will be issued and eligible to vest if the maximum target for total shareholder return, or TSR, over the 3-year measurement period is achieved. Depending on the ranking of our TSR compared to the respective TSRs of the companies comprising the Standard & Poor’s 500 Index during that period, the market-based PSUs issued could be up to 45 thousand shares.