Segment Net Sales (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Apr. 30, 2019 |
Apr. 30, 2018 |
|
| Segment Reporting Information [Line Items] | ||
| Net sales | $ 122,949 | $ 121,630 |
| Walmart U.S. | ||
| Segment Reporting Information [Line Items] | ||
| Net sales | 80,344 | 77,748 |
| Walmart International | ||
| Segment Reporting Information [Line Items] | ||
| Net sales | 28,775 | 30,260 |
| Sam's Club | ||
| Segment Reporting Information [Line Items] | ||
| Net sales | $ 13,830 | $ 13,622 |