Fair Value (Fair Value, Nonrecurring Measurement) (Details) - Level 3 - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Oct. 29, 2016 |
Oct. 24, 2015 |
|
| Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items] | ||
| Gains (losses) for assets measured on a nonrecurring basis | $ (89) | $ (17) |
| Investments in privately held companies (impaired) | Other Income (loss), net | ||
| Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items] | ||
| Gains (losses) for assets measured on a nonrecurring basis | (47) | (17) |
| Purchased intangible assets (impaired) | Cost of Sales and Operating Expenses | ||
| Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items] | ||
| Gains (losses) for assets measured on a nonrecurring basis | $ (42) | $ 0 |