v3.19.3.a.u2
Stock-Based Compensation - Summary of Equity Awards (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
12 Months Ended
Jan. 26, 2020
Jan. 27, 2019
Jan. 28, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Awards granted (in shares) 7    
Weighted average grant date fair value (in dollars per share) $ 184.47    
Shares purchased (in shares) 1 1 5
Summary of unearned SBC expense      
Aggregate unearned stock-based compensation expense, net of forfeitures $ 1,803 $ 1,580  
RSUs, PSUs and Market-based PSUs      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Awards granted (in shares) 7 4 6
Estimated total grant-date fair value $ 1,282 $ 1,109 $ 929
Weighted average grant date fair value (in dollars per share) $ 184.47 $ 258.26 $ 145.91
Summary of unearned SBC expense      
Estimated weighted average amortization period 2 years 6 months 2 years 2 months 12 days  
Employee Stock Purchase Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted average grant date fair value (in dollars per share) $ 64.87 $ 38.51 7.12
Weighted average price (in dollars per share) $ 148.76 $ 107.48 $ 21.24
Summary of unearned SBC expense      
Estimated weighted average amortization period 10 months 24 days 9 months 18 days  
Fair Value Assumptions      
Risk free interest rate, minimum 1.50% 1.60% 0.80%
Risk free interest rate, maximum 2.60% 2.80% 1.40%
Volatility rate, minimum 30.00% 24.00% 40.00%
Volatility rate, maximum 82.00% 75.00% 54.00%
Employee Stock Purchase Plan | Minimum      
Fair Value Assumptions      
Weighted average expected life (in years) 1 month 6 days 1 month 6 days 6 months
Dividend yield 0.30% 0.30% 0.30%
Employee Stock Purchase Plan | Maximum      
Fair Value Assumptions      
Weighted average expected life (in years) 2 years 2 years 2 years
Dividend yield 0.40% 0.40% 0.50%