Fair Value Measurements (Fair Value Measurements At Reporting Date) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Assets:
Unrealized derivative gains	$ 2,408	$ 2,676
Deferred receivables consideration	546	900
Liabilities:
Unrealized derivative losses	2,435	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	2,558	2,451
Deferred receivables consideration	0	0
Total Assets	3,893	3,877
Liabilities:
Inventory-related payables	0	0
Total Liabilities	1,498	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	1,335	1,426
Liabilities:
Unrealized derivative losses	1,498	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	3,419	5,291
Marketable securities	15	16
Deferred receivables consideration	546	900
Total Assets	4,786	7,314
Liabilities:
Inventory-related payables	324	903
Total Liabilities	1,028	1,756
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commodity Contracts [Member]
Assets:
Unrealized derivative gains	653	936
Liabilities:
Unrealized derivative losses	509	638
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign Exchange Contracts [Member]
Assets:
Unrealized derivative gains	152	170
Liabilities:
Unrealized derivative losses	195	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	1,926	1,745
Marketable securities	0	0
Deferred receivables consideration	0	0
Total Assets	2,193	1,888
Liabilities:
Inventory-related payables	63	33
Total Liabilities	296	171
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Commodity Contracts [Member]
Assets:
Unrealized derivative gains	267	143
Liabilities:
Unrealized derivative losses	233	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	5,345	7,036
Marketable securities	2,573	2,467
Deferred receivables consideration	546	900
Total Assets	10,872	13,079
Liabilities:
Inventory-related payables	387	936
Total Liabilities	2,822	3,527
Fair Value, Measurements, Recurring [Member] | Total Fair Value [Member] | Commodity Contracts [Member]
Assets:
Unrealized derivative gains	2,255	2,505
Liabilities:
Unrealized derivative losses	2,240	2,376
Fair Value, Measurements, Recurring [Member] | Total Fair Value [Member] | Foreign Exchange Contracts [Member]
Assets:
Unrealized derivative gains	152	170
Liabilities:
Unrealized derivative losses	195	215
Fair Value, Measurements, Recurring [Member] | Total Fair Value [Member] | Interest Rate Contracts [Member]
Assets:
Unrealized derivative gains	$ 1	$ 1