Revenues Revenues (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
Disaggregation of Revenue [Line Items]
Revenues	$ 17,978	$ 15,126	$ 16,281	$ 14,970	$ 16,329	$ 16,726	$ 16,297	$ 15,304	$ 64,355	$ 64,656	$ 64,341
Contract with Customer, Liability, Current	$ 626				$ 604				626	604
Contract with Customer, Liability, Revenue Recognized									604	575
Ag Services and Oilseeds [Member]
Disaggregation of Revenue [Line Items]
Revenues									49,716	48,741	49,891
Ag Services [Member]
Disaggregation of Revenue [Line Items]
Revenues										31,705	31,766
Crushing [Member]
Disaggregation of Revenue [Line Items]
Revenues										9,479	10,319
Refined Products and Other [Member]
Disaggregation of Revenue [Line Items]
Revenues										7,557	7,806
Carbohydrate Solutions [Member]
Disaggregation of Revenue [Line Items]
Revenues									8,472	9,886	10,279
Starches and sweeteners [Member]
Disaggregation of Revenue [Line Items]
Revenues										6,854	6,922
Vantage Corn Processors
Disaggregation of Revenue [Line Items]
Revenues										3,032	3,357
Nutrition [Member]
Disaggregation of Revenue [Line Items]
Revenues									5,800	5,677	3,790
Human Nutrition
Disaggregation of Revenue [Line Items]
Revenues										2,745	2,571
Animal Nutrition [Member]
Disaggregation of Revenue [Line Items]
Revenues										2,932	1,219
Other Segments [Member]
Disaggregation of Revenue [Line Items]
Revenues									367	352	381
Non MTM Products and Services [Member]
Disaggregation of Revenue [Line Items]
Revenues									19,101	22,389	17,774
Non MTM Products and Services [Member] | Ag Services and Oilseeds [Member]
Disaggregation of Revenue [Line Items]
Revenues									6,093	8,174	5,119
Non MTM Products and Services [Member] | Ag Services [Member]
Disaggregation of Revenue [Line Items]
Revenues									3,531	5,208	2,663
Non MTM Products and Services [Member] | Crushing [Member]
Disaggregation of Revenue [Line Items]
Revenues									467	736	664
Non MTM Products and Services [Member] | Refined Products and Other [Member]
Disaggregation of Revenue [Line Items]
Revenues									2,095	2,230	1,792
Non MTM Products and Services [Member] | Carbohydrate Solutions [Member]
Disaggregation of Revenue [Line Items]
Revenues									6,841	8,186	8,484
Non MTM Products and Services [Member] | Starches and sweeteners [Member]
Disaggregation of Revenue [Line Items]
Revenues									4,756	5,154	5,127
Non MTM Products and Services [Member] | Vantage Corn Processors
Disaggregation of Revenue [Line Items]
Revenues									2,085	3,032	3,357
Non MTM Products and Services [Member] | Nutrition [Member]
Disaggregation of Revenue [Line Items]
Revenues									5,800	5,677	3,790
Non MTM Products and Services [Member] | Human Nutrition
Disaggregation of Revenue [Line Items]
Revenues									2,812	2,745	2,571
Non MTM Products and Services [Member] | Animal Nutrition [Member]
Disaggregation of Revenue [Line Items]
Revenues									2,988	2,932	1,219
Non MTM Products and Services [Member] | Other Segments [Member]
Disaggregation of Revenue [Line Items]
Revenues									367	352	381
Non MTM Products and Services [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenues									18,678	21,874	17,293
Non MTM Products and Services [Member] | Transferred at Point in Time [Member] | Ag Services and Oilseeds [Member]
Disaggregation of Revenue [Line Items]
Revenues									5,670	7,659	4,638
Non MTM Products and Services [Member] | Transferred at Point in Time [Member] | Ag Services [Member]
Disaggregation of Revenue [Line Items]
Revenues									3,108	4,693	2,182
Non MTM Products and Services [Member] | Transferred at Point in Time [Member] | Crushing [Member]
Disaggregation of Revenue [Line Items]
Revenues									467	736	664
Non MTM Products and Services [Member] | Transferred at Point in Time [Member] | Refined Products and Other [Member]
Disaggregation of Revenue [Line Items]
Revenues									2,095	2,230	1,792
Non MTM Products and Services [Member] | Transferred at Point in Time [Member] | Carbohydrate Solutions [Member]
Disaggregation of Revenue [Line Items]
Revenues									6,841	8,186	8,484
Non MTM Products and Services [Member] | Transferred at Point in Time [Member] | Starches and sweeteners [Member]
Disaggregation of Revenue [Line Items]
Revenues									4,756	5,154	5,127
Non MTM Products and Services [Member] | Transferred at Point in Time [Member] | Vantage Corn Processors
Disaggregation of Revenue [Line Items]
Revenues									2,085	3,032	3,357
Non MTM Products and Services [Member] | Transferred at Point in Time [Member] | Nutrition [Member]
Disaggregation of Revenue [Line Items]
Revenues									5,800	5,677	3,790
Non MTM Products and Services [Member] | Transferred at Point in Time [Member] | Human Nutrition
Disaggregation of Revenue [Line Items]
Revenues									2,812	2,745	2,571
Non MTM Products and Services [Member] | Transferred at Point in Time [Member] | Animal Nutrition [Member]
Disaggregation of Revenue [Line Items]
Revenues									2,988	2,932	1,219
Non MTM Products and Services [Member] | Transferred at Point in Time [Member] | Other Segments [Member]
Disaggregation of Revenue [Line Items]
Revenues									367	352	381
Non MTM Products and Services [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenues									423	515	481
Non MTM Products and Services [Member] | Transferred over Time [Member] | Ag Services and Oilseeds [Member]
Disaggregation of Revenue [Line Items]
Revenues									423	515	481
Non MTM Products and Services [Member] | Transferred over Time [Member] | Ag Services [Member]
Disaggregation of Revenue [Line Items]
Revenues									423	515	481
Mark-to-Market Products [Member]
Disaggregation of Revenue [Line Items]
Revenues									45,254	42,267	46,567
Mark-to-Market Products [Member] | Ag Services and Oilseeds [Member]
Disaggregation of Revenue [Line Items]
Revenues									43,623	40,567	44,772
Mark-to-Market Products [Member] | Ag Services [Member]
Disaggregation of Revenue [Line Items]
Revenues									29,195	26,497	29,103
Mark-to-Market Products [Member] | Crushing [Member]
Disaggregation of Revenue [Line Items]
Revenues									9,126	8,743	9,655
Mark-to-Market Products [Member] | Refined Products and Other [Member]
Disaggregation of Revenue [Line Items]
Revenues									5,302	5,327	6,014
Mark-to-Market Products [Member] | Carbohydrate Solutions [Member]
Disaggregation of Revenue [Line Items]
Revenues									1,631	1,700	1,795
Mark-to-Market Products [Member] | Starches and sweeteners [Member]
Disaggregation of Revenue [Line Items]
Revenues									$ 1,631	$ 1,700	$ 1,795