Segment Information - Reconciling Items (Details) - USD ($) $ in Millions |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Jan. 26, 2020 |
Oct. 27, 2019 |
Jul. 28, 2019 |
Apr. 28, 2019 |
Jan. 27, 2019 |
Oct. 28, 2018 |
Jul. 29, 2018 |
Apr. 29, 2018 |
Jan. 26, 2020 |
Jan. 27, 2019 |
Jan. 28, 2018 |
|
| Segment Reporting Information [Line Items] | |||||||||||
| Unallocated revenue | $ 3,105 | $ 3,014 | $ 2,579 | $ 2,220 | $ 2,205 | $ 3,181 | $ 3,123 | $ 3,207 | $ 10,918 | $ 11,716 | $ 9,714 |
| Stock-based compensation expense | (844) | (557) | (391) | ||||||||
| Income from operations | 2,846 | 3,804 | 3,210 | ||||||||
| All Other | |||||||||||
| Segment Reporting Information [Line Items] | |||||||||||
| Unallocated revenue | 0 | 0 | 43 | ||||||||
| Stock-based compensation expense | (844) | (557) | (391) | ||||||||
| Unallocated cost of revenue and operating expenses | (267) | (277) | (237) | ||||||||
| Acquisition-related and other costs | (30) | (2) | (15) | ||||||||
| Legal settlement costs | (15) | (44) | 0 | ||||||||
| Income from operations | $ (1,156) | $ (880) | $ (600) | ||||||||