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Notes Payable, Long-Term Debt, Commitments and Contingencies (Details) $ in Millions				9 Months Ended
	Sep. 25, 2018 USD ($)	Jun. 28, 2018 item	May 15, 2018 USD ($)	Sep. 29, 2018 USD ($) item	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 04, 2015 USD ($)	Sep. 19, 2012 item
Debt Instrument
Total long-term debt at face value				$ 752		$ 536
Current maturities of long-term debt and unamortized discount				(11)		(54)
Long-term debt, less current maturities and unamortized discount				741		482
Proceeds from long-term debt				222	$ 38
Contingencies
Assets				$ 5,435		$ 5,161
Number of search warrants executed authorizing the seizure of certain records from Seaboard's offices in Merriam, Kansas and at the Seaboard Foods employment office and the human resources department in Guymon, Oklahoma. \| item								3
Number of civil or criminal proceedings or charges filed \| item				0
Pork Product Purchasers \| Pending Litigation
Contingencies
Number of plaintiffs \| item		11
Number of consolidated putative class actions \| item				3
Cereoil Bankruptcy Trustee - Case One \| Pending Litigation
Contingencies
Damages sought				$ 22
Cereoil
Contingencies
Percentage of ownership				45.00%
Cereoil \| Cereoil Bankruptcy Trustee - Case Two \| Pending Litigation
Contingencies
Damages sought				$ 23
Liabilities				53
Assets				30
Nolston
Contingencies
Percentage of ownership			45.00%
Nolston \| Nolston Bankruptcy Trustee \| Pending Litigation
Contingencies
Damages sought			$ 14
Liabilities			29
Assets			$ 15
Notes payable to bank
Debt Instrument
Notes payable outstanding				$ 162
Weighted average interest rate (as a percent)				10.63%		10.48%
Uncommitted bank lines
Debt Instrument
Notes payable outstanding				$ 162
Maximum capacity				582
Letters of credit outstanding				23
Committed bank line
Debt Instrument
Notes payable outstanding				0
Maximum capacity				100
Term loan due 2028
Debt Instrument
Maximum debt to capitalization ratio allowed	50.00%
Minimum net worth base requirement	$ 2,500
Percentage of consolidated net income added to net worth base amount	25.00%
Maximum dividends per year	$ 100
Total long-term debt at face value	700			$ 700
Proceeds from long-term debt	$ 220
Term loan due 2028 \| Maximum
Debt Instrument
Indebtedness as a percentage of consolidated tangible net worth	15
Term loan due 2022
Debt Instrument
Total long-term debt at face value						$ 484	$ 500
Effective interest rate (as a percent)				3.84%		3.20%
Foreign subsidiary obligations due 2019 through 2023
Debt Instrument
Total long-term debt at face value				$ 52		$ 52
Effective interest rate (as a percent)				4.22%		21.80%
Foreign subsidiaries \| Notes payable to bank \| Denominated in South African Rand
Debt Instrument
Notes payable outstanding				$ 71
Foreign subsidiaries \| Notes payable to bank \| Denominated in Argentine pesos
Debt Instrument
Notes payable outstanding				19
Foreign subsidiaries \| Notes payable to bank \| Denominated in Canadian dollars
Debt Instrument
Notes payable outstanding				22
Foreign subsidiaries \| Notes payable to bank \| Denominated in Zambian kwacha
Debt Instrument
Notes payable outstanding				5
Foreign subsidiaries \| Notes payable to bank \| Denominated in Euros
Debt Instrument
Notes payable outstanding				2
Foreign subsidiaries \| Uncommitted bank lines
Debt Instrument
Maximum capacity				$ 497
Foreign subsidiaries \| Mimran \| Denominated in Euros
Debt Instrument
Interest rate (as a percent)				3.25%
Total long-term debt at face value				$ 45