Segment and Geographic Information (Segment Information) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Information
Property, Plant and Equipment, Additions									$ 817	$ 817
Revenues	$ 17,978	$ 15,126	$ 16,281	$ 14,970	$ 16,329	$ 16,726	$ 16,297	$ 15,304	64,355	64,656	$ 64,341
Depreciation									803	827	812
Asset Abandonments and Impairments									28	131	100
Interest income									88	192	162
Equity in earnings of affiliates									579	454	518
Interest Expense									(339)	(402)	(364)
Operating profit									1,883	1,588	2,060
Investments in and advances to affiliates	4,913				5,132				4,913	5,132
Assets	49,719				43,997				49,719	43,997
Ag Services and Oilseeds [Member]
Segment Information
Revenues									49,716	48,741	49,891
Carbohydrate Solutions [Member]
Segment Information
Revenues									8,472	9,886	10,279
Nutrition [Member]
Segment Information
Revenues									5,800	5,677	3,790
Other Segments [Member]
Segment Information
Revenues									367	352	381
Operating Segments [Member]
Segment Information
Operating profit									3,455	2,948	3,273
Operating Segments [Member] | Ag Services and Oilseeds [Member]
Segment Information
Property, Plant and Equipment, Additions									261	271
Revenues									55,667	54,633	56,591
Depreciation									351	361	372
Asset Abandonments and Impairments									8	130	40
Interest income									39	51	45
Equity in earnings of affiliates									475	378	421
Operating profit									2,105	1,935	2,020
Investments in and advances to affiliates	4,402				4,662				4,402	4,662
Assets	24,792				21,397				24,792	21,397
Operating Segments [Member] | Carbohydrate Solutions [Member]
Segment Information
Property, Plant and Equipment, Additions									251	275
Revenues									9,423	11,154	11,421
Depreciation									305	320	328
Asset Abandonments and Impairments									0	1	0
Interest income									0	0	1
Equity in earnings of affiliates									81	60	62
Operating profit									717	644	945
Investments in and advances to affiliates	392				363				392	363
Assets	5,963				6,032				5,963	6,032
Operating Segments [Member] | Nutrition [Member]
Segment Information
Property, Plant and Equipment, Additions									149	166
Revenues									5,959	5,786	3,836
Depreciation									114	113	80
Asset Abandonments and Impairments									13	0	11
Interest income									2	1	2
Equity in earnings of affiliates									22	17	17
Operating profit									574	418	339
Investments in and advances to affiliates	102				98				102	98
Assets	8,652				8,622				8,652	8,622
Operating Segments [Member] | Other Segments [Member]
Segment Information
Property, Plant and Equipment, Additions									8	2
Revenues									367	352	381
Depreciation									6	6	6
Interest income									40	125	100
Operating profit									52	85	58
Assets	7,152				5,661				7,152	5,661
Intersegment Eliminations [Member]
Segment Information
Revenues									(7,061)	(7,269)	(7,888)
Intersegment Eliminations [Member] | Ag Services and Oilseeds [Member]
Segment Information
Revenues									(5,951)	(5,892)	(6,700)
Intersegment Eliminations [Member] | Carbohydrate Solutions [Member]
Segment Information
Revenues									(951)	(1,268)	(1,142)
Intersegment Eliminations [Member] | Nutrition [Member]
Segment Information
Revenues									(159)	(109)	(46)
Corporate, Non-Segment [Member]
Segment Information
Property, Plant and Equipment, Additions									148	103
Depreciation									27	27	26
Asset Abandonments and Impairments									7	0	49
Interest income									7	15	14
Equity in earnings of affiliates									1	(1)	18
Operating profit									(1,572)	(1,360)	(1,213)
Investments in and advances to affiliates	17				9				17	9
Assets	$ 3,160				$ 2,285				3,160	2,285
Nonoperating Income (Expense) [Member] | Segment Reconciling Items [Member]
Segment Information
Operating profit									83	12	13
Asset impairment, restructuring, and settlement [Member] | Segment Reconciling Items [Member]
Segment Information
Operating profit									(76)	(146)	(102)
Ag Services [Member] | Ag Services and Oilseeds [Member]
Segment Information
Revenues									32,726	31,705	31,766
Crushing [Member] | Ag Services and Oilseeds [Member]
Segment Information
Revenues									9,593	9,479	10,319
Refined Products and Other [Member] | Ag Services and Oilseeds [Member]
Segment Information
Revenues									7,397	7,557	7,806
Starches and sweeteners [Member] | Carbohydrate Solutions [Member]
Segment Information
Revenues									6,387	6,854	6,922
Bioproducts [Member] | Carbohydrate Solutions [Member]
Segment Information
Revenues									2,085	3,032	3,357
Wild and Specialty Ingredients [Member] | Nutrition [Member]
Segment Information
Revenues									2,812	2,745	2,571
Animal Nutrition [Member] | Nutrition [Member]
Segment Information
Revenues									$ 2,988	$ 2,932	$ 1,219