Acquisitions - Fair Value Measurement, Contingent Consideration, Significant Unobservable Inputs (Details) $ in Millions	Jul. 31, 2020 USD ($)	Apr. 24, 2020 USD ($)	Jul. 26, 2019 USD ($)	Apr. 26, 2019 USD ($)
Fair Value Inputs, Liabilities, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Contingent consideration, fair value	$ 297	$ 280	$ 269	$ 222
Revenue and other performance-based payments | Recurring | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Contingent consideration, fair value	$ 116
Revenue and other performance-based payments | Recurring | Level 3 | Probability of payment
Fair Value Inputs
Contingent consideration, significant unobservable inputs	1
Revenue and other performance-based payments | Minimum | Recurring | Level 3 | Discount rate
Fair Value Inputs
Contingent consideration, significant unobservable inputs	0.140
Revenue and other performance-based payments | Maximum | Recurring | Level 3 | Discount rate
Fair Value Inputs
Contingent consideration, significant unobservable inputs	0.324
Revenue and other performance-based payments | Weighted Average | Recurring | Level 3 | Discount rate
Fair Value Inputs
Contingent consideration, significant unobservable inputs	0.223
Revenue and other performance-based payments | Weighted Average | Recurring | Level 3 | Probability of payment
Fair Value Inputs
Contingent consideration, significant unobservable inputs	1
Product development and other milestone-based payments | Recurring | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Contingent consideration, fair value	$ 181
Product development and other milestone-based payments | Recurring | Level 3 | Discount rate
Fair Value Inputs
Contingent consideration, significant unobservable inputs	0.055
Product development and other milestone-based payments | Minimum | Recurring | Level 3 | Probability of payment
Fair Value Inputs
Contingent consideration, significant unobservable inputs	0.50
Product development and other milestone-based payments | Maximum | Recurring | Level 3 | Probability of payment
Fair Value Inputs
Contingent consideration, significant unobservable inputs	1
Product development and other milestone-based payments | Weighted Average | Recurring | Level 3 | Discount rate
Fair Value Inputs
Contingent consideration, significant unobservable inputs	0.055
Product development and other milestone-based payments | Weighted Average | Recurring | Level 3 | Probability of payment
Fair Value Inputs
Contingent consideration, significant unobservable inputs	0.905