Fair Value Measurements (Fair Value Measurements At Reporting Date) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Assets:
Derivative Asset	$ 624	$ 636
Deferred receivables consideration	447	379
Liabilities:
Derivative Liability	768	761
Fair Value, Recurring [Member]
Assets:
Inventories carried at market	3,988	4,547
Cash Equivalents, at Carrying Value	429	1,288
Available-for-sale Securities, Fair Value Disclosure	12	13
Restricted Investments, at Fair Value	925	1,044
Deferred receivables consideration	447	379
Total Assets	6,425	7,907
Liabilities:
Inventory-related payables	762	597
Total Liabilities	1,530	1,358
Fair Value, Recurring [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	461	461
Liabilities:
Derivative Liability	609	589
Fair Value, Recurring [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative Asset	160	175
Liabilities:
Derivative Liability	113	152
Fair Value, Recurring [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	3
Liabilities:
Derivative Liability	46	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	429	1,288
Available-for-sale Securities, Fair Value Disclosure	11	12
Restricted Investments, at Fair Value	925	1,044
Deferred receivables consideration	0	0
Total Assets	1,365	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	2,600	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	447	379
Total Assets	3,513	3,893
Liabilities:
Inventory-related payables	740	579
Total Liabilities	1,292	1,095
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	302	306
Liabilities:
Derivative Liability	393	344
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative Asset	160	175
Liabilities:
Derivative Liability	113	152
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	3
Liabilities:
Derivative Liability	46	20
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Inventories carried at market	1,388	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	1,547	1,670
Liabilities:
Inventory-related payables	22	18
Total Liabilities	238	263
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	159	155
Liabilities:
Derivative Liability	216	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