Fair Value Measurements (Fair Value Measurements At Reporting Date) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Assets:
Unrealized derivative gains	$ 2,608	$ 2,676
Deferred receivables consideration	487	900
Liabilities:
Unrealized derivative losses	2,762	2,591
Fair Value, Measurements, Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Assets:
Inventories carried at market	0	0
Marketable securities	2,557	2,451
Deferred receivables consideration	0	0
Total Assets	3,921	3,877
Liabilities:
Inventory-related payables	0	0
Total Liabilities	1,667	1,600
Fair Value, Measurements, Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Commodity Contracts [Member]
Assets:
Unrealized derivative gains	1,364	1,426
Liabilities:
Unrealized derivative losses	1,667	1,600
Fair Value, Measurements, Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Foreign Exchange Contracts [Member]
Assets:
Unrealized derivative gains	0	0
Liabilities:
Unrealized derivative losses	0	0
Fair Value, Measurements, Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Interest Rate Contracts [Member]
Assets:
Unrealized derivative gains	0	0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets:
Inventories carried at market	3,654	5,291
Marketable securities	17	16
Deferred receivables consideration	487	900
Total Assets	5,140	7,314
Liabilities:
Inventory-related payables	299	903
Total Liabilities	1,208	1,756
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commodity Contracts [Member]
Assets:
Unrealized derivative gains	748	936
Liabilities:
Unrealized derivative losses	708	638
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign Exchange Contracts [Member]
Assets:
Unrealized derivative gains	233	170
Liabilities:
Unrealized derivative losses	201	215
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Contracts [Member]
Assets:
Unrealized derivative gains	1	1
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Inventories carried at market	1,272	1,745
Marketable securities	0	0
Deferred receivables consideration	0	0
Total Assets	1,534	1,888
Liabilities:
Inventory-related payables	9	33
Total Liabilities	195	171
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Commodity Contracts [Member]
Assets:
Unrealized derivative gains	262	143
Liabilities:
Unrealized derivative losses	186	138
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Foreign Exchange Contracts [Member]
Assets:
Unrealized derivative gains	0	0
Liabilities:
Unrealized derivative losses	0	0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Interest Rate Contracts [Member]
Assets:
Unrealized derivative gains	0	0
Fair Value, Measurements, Recurring [Member] | Total Fair Value [Member]
Assets:
Inventories carried at market	4,926	7,036
Marketable securities	2,574	2,467
Deferred receivables consideration	487	900
Total Assets	10,595	13,079
Liabilities:
Inventory-related payables	308	936
Total Liabilities	3,070	3,527
Fair Value, Measurements, Recurring [Member] | Total Fair Value [Member] | Commodity Contracts [Member]
Assets:
Unrealized derivative gains	2,374	2,505
Liabilities:
Unrealized derivative losses	2,561	2,376
Fair Value, Measurements, Recurring [Member] | Total Fair Value [Member] | Foreign Exchange Contracts [Member]
Assets:
Unrealized derivative gains	233	170
Liabilities:
Unrealized derivative losses	201	215
Fair Value, Measurements, Recurring [Member] | Total Fair Value [Member] | Interest Rate Contracts [Member]
Assets:
Unrealized derivative gains	$ 1	$ 1