Fair Value Measurements (Fair Value Measurements At Reporting Date) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Assets:
Derivative Asset	$ 1,270	$ 758
Available-for-sale Securities, Fair Value Disclosure	883	877
Deferred receivables consideration	403	513
Liabilities:
Derivative Liability	1,437	605
Fair Value, Measurements, Recurring [Member]
Assets:
Inventories carried at market	4,171	4,066
Cash Equivalents, at Carrying Value	40	328
Available-for-sale Securities, Fair Value Disclosure	882	873
Restricted Investments, at Fair Value	1,633	1,938
Deferred receivables consideration	403	513
Total Assets	8,399	8,476
Liabilities:
Inventory-related payables	257	721
Total Liabilities	1,694	1,326
Fair Value, Measurements, Recurring [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	1,120	646
Liabilities:
Derivative Liability	1,190	419
Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative Asset	109	93
Liabilities:
Derivative Liability	247	186
Fair Value, Measurements, Recurring [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	41	19
Fair Value, Measurements, 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	40	328
Available-for-sale Securities, Fair Value Disclosure	810	698
Restricted Investments, at Fair Value	1,633	1,938
Deferred receivables consideration	0	0
Total Assets	2,483	2,965
Liabilities:
Inventory-related payables	0	0
Total Liabilities	7	0
Fair Value, Measurements, 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, Measurements, Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative Asset	0	1
Liabilities:
Derivative Liability	7	0
Fair Value, Measurements, Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	0	0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets:
Inventories carried at market	3,072	3,062
Cash Equivalents, at Carrying Value	0	0
Available-for-sale Securities, Fair Value Disclosure	72	175
Restricted Investments, at Fair Value	0	0
Deferred receivables consideration	403	513
Total Assets	4,664	4,264
Liabilities:
Inventory-related payables	245	705
Total Liabilities	1,175	1,197
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	967	403
Liabilities:
Derivative Liability	690	306
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative Asset	109	92
Liabilities:
Derivative Liability	240	186
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	41	19
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Inventories carried at market	1,099	1,004
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	1,252	1,247
Liabilities:
Inventory-related payables	12	16
Total Liabilities	512	129
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	153	243
Liabilities:
Derivative Liability	500	113
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative Asset	0	0
Liabilities:
Derivative Liability	0	0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	$ 0	$ 0