Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Jan. 31, 2021	Jun. 27, 2020
Document and Entity Information
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 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, City or Town	Merriam
Entity Address, State or Province	KS
Entity Address, Postal Zip Code	66202
City Area Code	913
Local Phone Number	676-8800
Title of 12(b) Security	Common Stock $1.00 Par Value
Trading Symbol	SEB
Security Exchange Name	NYSEAMER
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		1,160,779
Entity Public Float			$ 741,867,137
Entity Central Index Key	0000088121
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false