Fair Value Measurements (Fair Value Measurements At Reporting Date) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Assets:
Available-for-sale Securities, Fair Value Disclosure	$ 801	$ 1,000
Deferred receivables consideration	703	511
Fair Value, Measurements, Recurring [Member]
Assets:
Inventories carried at market	4,054	4,699
Cash Equivalents, at Carrying Value	177	491
Available-for-sale Securities, Fair Value Disclosure	795	940
Restricted Investments, at Fair Value	2,087	2,158
Deferred receivables consideration	703	511
Total Assets	8,811	9,696
Liabilities:
Inventory-related payables	358	652
Total Liabilities	1,442	1,578
Fair Value, Measurements, Recurring [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	867	690
Derivative Liability	934	776
Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative Asset	108	186
Derivative Liability	150	150
Fair Value, Measurements, Recurring [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	20	21
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	177	491
Available-for-sale Securities, Fair Value Disclosure	715	860
Restricted Investments, at Fair Value	2,087	2,158
Deferred receivables consideration	0	0
Total Assets	2,979	3,509
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
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	0
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	3,028	3,208
Available-for-sale Securities, Fair Value Disclosure	80	80
Deferred receivables consideration	703	511
Total Assets	4,652	4,493
Liabilities:
Inventory-related payables	345	612
Total Liabilities	1,059	1,326
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	713	487
Derivative Liability	571	564
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative Asset	108	186
Derivative Liability	143	150
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	20	21
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Inventories carried at market	1,026	1,491
Available-for-sale Securities, Fair Value Disclosure	0	0
Deferred receivables consideration	0	0
Total Assets	1,180	1,694
Liabilities:
Inventory-related payables	13	40
Total Liabilities	376	252
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	154	203
Derivative Liability	363	212
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative Asset	0	0
Derivative Liability	0	0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	$ 0	$ 0