Fair Value Measurements (Reconciliation Of Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Liabilities Measured on Recurring Basis, Change in Unrealized Gain (Loss)	$ 111		$ 127		$ 397		$ 237
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	181		296		295		171
Total increase (decrease) in unrealized losses included in cost of products sold	110	[1]	127	[2]	394	[3]	191	[4]
Purchases	12		4		18		190
Sales	(11)		(17)		(42)		(23)
Settlements	(130)		(186)		(580)		(397)
Transfers into Level 3	127		30		234		104
Transfers out of Level 3	(8)		(59)		(38)		(41)
Balance at end of period	281		195		281		195
Significant Unobservable Inputs (Level 3) [Member] | Inventory Related Payables [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	19		63		34		33
Total increase (decrease) in unrealized losses included in cost of products sold	0	[1]	0	[2]	10	[3]	(191)	[4]
Purchases	12		4		18		190
Sales	(11)		(17)		(42)		(23)
Settlements	0		0		0		0
Transfers into Level 3	0		0		0		0
Transfers out of Level 3	0		(41)		0		0
Balance at end of period	20		9		20		9
Significant Unobservable Inputs (Level 3) [Member] | Commodity Derivative Contracts Losses [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	162		233		261		138
Total increase (decrease) in unrealized losses included in cost of products sold	110	[1]	127	[2]	384	[3]	382	[4]
Purchases	0		0		0		0
Sales	0		0		0		0
Settlements	(130)		(186)		(580)		(397)
Transfers into Level 3	127		30		234		104
Transfers out of Level 3	(8)		(18)		(38)		(41)
Balance at end of period	$ 261		$ 186		$ 261		$ 186

[1] Includes increase in unrealized losses of $111 million relating to Level 3 liabilities still held at September 30, 2014.

[2] * Includes increase in unrealized losses of $127 million relating to Level 3 liabilities still held at September 30, 2013.

[3] * Includes increase in unrealized losses of $397 million relating to Level 3 liabilities still held at September 30, 2014.

[4] * Includes increase in unrealized losses of $237 million relating to Level 3 liabilities still held at September 30, 2013.