| Cover | Mar. 04, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Mar. 4, 2021 |
| Entity File Number | 1-303 |
| Entity Registrant Name | KROGER CO. |
| Entity Central Index Key | 0000056873 |
| Entity Tax Identification Number | 31-0345740 |
| Entity Incorporation, State or Country Code | OH |
| Entity Address, Address Line One | 1014 Vine Street |
| Entity Address, City or Town | Cincinnati |
| Entity Address, State or Province | OH |
| Entity Address, Postal Zip Code | 45202 |
| City Area Code | 513 |
| Local Phone Number | 762-4000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock $1 par value |
| Trading Symbol | KR |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
