| Document And Entity Information | Sep. 25, 2019 |
| Document And Entity Information [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Sep. 25, 2019 |
| Entity Registrant Name | BEST BUY CO., INC. |
| Entity Incorporation, State or Country Code | MN |
| Entity File Number | 1-9595 |
| Entity Tax Identification Number | 41-0907483 |
| Entity Address, Address Line One | 7601 Penn Avenue South |
| Entity Address, City or Town | Richfield |
| Entity Address, State or Province | MN |
| Entity Address, Postal Zip Code | 55423 |
| City Area Code | 612 |
| Local Phone Number | 291-1000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.10 par value per share |
| Trading Symbol | BBY |
| Security Exchange Name | NYSE |
| Entity Central Index Key | 0000764478 |
| Entity Emerging Growth Company | false |
| Amendment Flag | false |
