Fair Value Measurements (Fair Value Measurements At Reporting Date) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Assets:
Available-for-sale Securities, Fair Value Disclosure	$ 989	$ 941
Deferred receivables consideration	(573)	(757)
Fair Value, Measurements, Recurring [Member]
Assets:
Inventories carried at market	6,645	6,059
Cash Equivalents, at Carrying Value	506	2,518
Available-for-sale Securities, Fair Value Disclosure	937	907
Restricted Investments, at Fair Value	1,656	1,707
Deferred receivables consideration	573	757
Total Assets	11,445	12,917
Liabilities:
Inventory-related payables	490	742
Total Liabilities	1,446	1,566
Fair Value, Measurements, Recurring [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	995	850
Derivative Liability	811	649
Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative Asset	132	118
Derivative Liability	140	166
Fair Value, Measurements, Recurring [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	1	1
Derivative Liability	5	9
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	506	2,518
Available-for-sale Securities, Fair Value Disclosure	851	881
Restricted Investments, at Fair Value	1,656	1,707
Deferred receivables consideration	0	0
Total Assets	3,013	5,167
Liabilities:
Inventory-related payables	0	0
Total Liabilities	2	45
Fair Value, Measurements, Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	0	31
Derivative Liability	0	45
Fair Value, Measurements, Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative Asset	0	30
Derivative Liability	2	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
Derivative Liability	0	0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets:
Inventories carried at market	4,774	4,247
Available-for-sale Securities, Fair Value Disclosure	86	26
Deferred receivables consideration	573	757
Total Assets	6,309	5,659
Liabilities:
Inventory-related payables	463	708
Total Liabilities	1,097	1,226
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	743	540
Derivative Liability	491	343
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative Asset	132	88
Derivative Liability	138	166
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	1	1
Derivative Liability	5	9
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Inventories carried at market	1,871	1,812
Available-for-sale Securities, Fair Value Disclosure	0	0
Deferred receivables consideration	0	0
Total Assets	2,123	2,091
Liabilities:
Inventory-related payables	27	34
Total Liabilities	347	295
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	252	279
Derivative Liability	320	261
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
Derivative Liability		$ 0