Fair Value Measurements (Fair Value Measurements At Reporting Date) (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Assets:
Derivative Asset	$ 535	$ 624
Available-for-sale Securities, Fair Value Disclosure	436	483
Deferred receivables consideration	353	540
Liabilities:
Derivative Liability	581	651
Fair Value, Measurements, Recurring [Member]
Assets:
Inventories carried at market	4,143	4,424
Cash Equivalents, at Carrying Value	22	286
Available-for-sale Securities, Fair Value Disclosure	436	477
Restricted Investments, at Fair Value	1,492	1,613
Deferred receivables consideration	353	540
Total Assets	6,981	7,964
Liabilities:
Inventory-related payables	361	521
Total Liabilities	942	1,172
Fair Value, Measurements, Recurring [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	444	511
Liabilities:
Derivative Liability	471	561
Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative Asset	83	102
Liabilities:
Derivative Liability	110	90
Fair Value, Measurements, Recurring [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	8	11
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	22	286
Available-for-sale Securities, Fair Value Disclosure	346	408
Restricted Investments, at Fair Value	1,492	1,613
Deferred receivables consideration	0	0
Total Assets	1,860	2,307
Liabilities:
Inventory-related payables	0	0
Total Liabilities	1	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	1	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
Liabilities:
Derivative Liability	0	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	3,143	3,102
Cash Equivalents, at Carrying Value	0	0
Available-for-sale Securities, Fair Value Disclosure	90	69
Restricted Investments, at Fair Value	0	0
Deferred receivables consideration	353	540
Total Assets	4,015	4,195
Liabilities:
Inventory-related payables	329	491
Total Liabilities	755	1,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	338	371
Liabilities:
Derivative Liability	316	419
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative Asset	83	102
Liabilities:
Derivative Liability	110	90
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Contracts [Member]
Assets:
Derivative Asset	8	11
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Inventories carried at market	1,000	1,322
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	1,106	1,462
Liabilities:
Inventory-related payables	32	30
Total Liabilities	186	172
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Commodity Contracts [Member]
Assets:
Derivative Asset	106	140
Liabilities:
Derivative Liability	154	142
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