Acquisitions - Fair Value Measurement, Contingent Consideration, Significant Unobservable Inputs (Details) $ in Millions	Oct. 26, 2018 USD ($)	Jul. 27, 2018 USD ($)	Apr. 27, 2018 USD ($)	Oct. 27, 2017 USD ($)	Jul. 28, 2017 USD ($)	Apr. 28, 2017 USD ($)
Fair Value Inputs, Liabilities, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Contingent consideration, fair value	$ 203	$ 208	$ 173	$ 190	$ 242	$ 246
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	$ 104
Revenue and other performance-based payments | Recurring | Level 3 | Probability of payment
Fair Value Inputs
Contingent consideration, significant unobservable inputs	1.00
Revenue and other performance-based payments | Minimum | Recurring | Level 3 | Discount rate
Fair Value Inputs
Contingent consideration, significant unobservable inputs	0.115
Revenue and other performance-based payments | Maximum | Recurring | Level 3 | Discount rate
Fair Value Inputs
Contingent consideration, significant unobservable inputs	0.325
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	$ 99
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	0.75
Product development and other milestone-based payments | Maximum | Recurring | Level 3 | Probability of payment
Fair Value Inputs
Contingent consideration, significant unobservable inputs	1.00