Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 31, 2018	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Data
Net sales	$ 1,812	$ 1,663	$ 1,822	$ 1,543	$ 1,662	$ 1,651	$ 1,691	$ 1,579	$ 6,840	$ 6,583	$ 5,809
Operating income (loss)	91	(6)	53	(34)	43	37	32	97	104	209	240
Net earnings (loss) attributable to Seaboard	$ 175	$ (7)	$ 58	$ 57	$ (91)	$ 35	$ 7	$ 32	$ 283	$ (17)	$ 247
Earnings (loss) per common share	$ 149.91	$ (6.00)	$ 50.13	$ 48.79	$ (77.58)	$ 29.93	$ 6.28	$ 26.75	$ 242.78	$ (14.61)	$ 211.01
Federal blender's credits recognized as revenue	$ 60
Federal blender's credits recognized as revenue per common share	$ 51.14
Other investment income (loss), net	$ 73				$ (167)				$ 225	$ (152)	$ 177