Fair Value Measurements (Fair Value Measurements At Reporting Date) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Assets:
Deferred receivables consideration	$ 0	$ 446
Fair Value, Recurring [Member]
Assets:
Inventories carried at market	7,941	4,704
Cash Equivalents	297	505
Debt Securities, Available-for-sale	1	5
Segregated investments	1,067	628
Deferred receivables consideration		446
Total Assets	12,414	6,907
Liabilities:
Inventory-related payables	509	729
Total Liabilities	3,127	1,471
Fair Value, Recurring [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	2,764	478
Liabilities:
Derivative Liability	2,034	574
Fair Value, Recurring [Member] | Foreign Exchange Contract [Member]
Assets:
Derivative Asset	283	138
Liabilities:
Derivative Liability	535	125
Fair Value, Recurring [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	61	3
Liabilities:
Derivative Liability	15	43
Fair Value, Recurring [Member] | Embedded Derivative Financial Instruments
Liabilities:
Derivative Liability	34
Fair Value, Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Assets:
Inventories carried at market	0	0
Cash Equivalents	297	505
Debt Securities, Available-for-sale	1	5
Segregated investments	1,067	628
Deferred receivables consideration		0
Total Assets	1,365	1,138
Liabilities:
Inventory-related payables	0	0
Total Liabilities	0	0
Fair Value, Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	0	0
Liabilities:
Derivative Liability	0	0
Fair Value, Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Foreign Exchange Contract [Member]
Assets:
Derivative Asset	0	0
Liabilities:
Derivative Liability	0	0
Fair Value, Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	0
Liabilities:
Derivative Liability	0	0
Fair Value, Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Embedded Derivative Financial Instruments
Liabilities:
Derivative Liability	0
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets:
Inventories carried at market	5,758	3,227
Debt Securities, Available-for-sale	0	0
Segregated investments	0
Deferred receivables consideration		446
Total Assets	8,007	4,091
Liabilities:
Inventory-related payables	498	702
Total Liabilities	2,164	1,245
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	1,905	277
Liabilities:
Derivative Liability	1,116	375
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign Exchange Contract [Member]
Assets:
Derivative Asset	283	138
Liabilities:
Derivative Liability	535	125
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	61	3
Liabilities:
Derivative Liability	15	43
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Embedded Derivative Financial Instruments
Liabilities:
Derivative Liability	0
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Inventories carried at market	2,183	1,477
Debt Securities, Available-for-sale	0	0
Deferred receivables consideration		0
Total Assets	3,042	1,678
Liabilities:
Inventory-related payables	11	27
Total Liabilities	963	226
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	859	201
Liabilities:
Derivative Liability	918	199
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Foreign Exchange Contract [Member]
Assets:
Derivative Asset	0	0
Liabilities:
Derivative Liability	0	0
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	0
Liabilities:
Derivative Liability	0	$ 0
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Embedded Derivative Financial Instruments
Liabilities:
Derivative Liability	$ 34