| Document and Entity Information | Dec. 02, 2020 |
| Document and Entity Information | |
| Document Type | 8-K/A |
| Document Period End Date | Dec. 2, 2020 |
| Entity File Number | 1-3390 |
| Entity Registrant Name | Seaboard Corporation |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 04-2260388 |
| Entity Address, Address Line One | 9000 West 67th Street |
| Entity Address, State or Province | KS |
| Entity Address, City or Town | Merriam |
| Entity Address, Postal Zip Code | 66202 |
| City Area Code | 913 |
| Local Phone Number | 676-8800 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock $1.00 Par Value |
| Trading Symbol | SEB |
| Security Exchange Name | NYSEAMER |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000088121 |
| Amendment Flag | false |
