Fair Value Measurements (Fair Value Measurements At Reporting Date) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Assets:
Derivative Asset	$ 599	$ 636
Deferred Receivables Consideration	330	379
Liabilities:
Derivative Liability	642	761
Fair Value, Recurring [Member]
Assets:
Inventories carried at market	4,043	4,547
Cash Equivalents, at Carrying Value	490	1,288
Available-for-sale Securities, Fair Value Disclosure	36	13
Restricted Investments, at Fair Value	777	1,044
Deferred Receivables Consideration	330	379
Total Assets	6,275	7,907
Liabilities:
Inventory-related payables	618	597
Total Liabilities	1,260	1,358
Fair Value, Recurring [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	424	461
Liabilities:
Derivative Liability	471	589
Fair Value, Recurring [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative Asset	171	175
Liabilities:
Derivative Liability	128	152
Fair Value, Recurring [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	4
Liabilities:
Derivative Liability	43	20
Fair Value, Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Assets:
Inventories carried at market	0	0
Cash Equivalents, at Carrying Value	490	1,288
Available-for-sale Securities, Fair Value Disclosure	35	12
Restricted Investments, at Fair Value	777	1,044
Deferred Receivables Consideration	0	0
Total Assets	1,302	2,344
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 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] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	0
Liabilities:
Derivative Liability	0	0
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets:
Inventories carried at market	2,613	3,032
Cash Equivalents, at Carrying Value	0	0
Available-for-sale Securities, Fair Value Disclosure	1	1
Restricted Investments, at Fair Value	0	0
Deferred Receivables Consideration	330	379
Total Assets	3,382	3,893
Liabilities:
Inventory-related payables	577	579
Total Liabilities	1,079	1,095
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	263	306
Liabilities:
Derivative Liability	331	344
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative Asset	171	175
Liabilities:
Derivative Liability	128	152
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	4
Liabilities:
Derivative Liability	43	20
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Inventories carried at market	1,430	1,515
Cash Equivalents, at Carrying Value	0	0
Available-for-sale Securities, Fair Value Disclosure	0	0
Restricted Investments, at Fair Value	0	0
Deferred Receivables Consideration	0	0
Total Assets	1,591	1,670
Liabilities:
Inventory-related payables	41	18
Total Liabilities	181	263
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	161	155
Liabilities:
Derivative Liability	140	245
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Foreign Exchange Contracts [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