Fair Value Measurements (Reconciliation Of Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 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)	$ 58		$ 8		$ 286		$ 110
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	347		387		295		171
Total increase (decrease) in unrealized losses included in cost of products sold	52	[1]	(24)	[2]	284	[3]	104	[4]
Purchases	2		10		6		186
Sales	(13)		(2)		(31)		(6)
Settlements	(238)		(109)		(450)		(211)
Transfers into Level 3	41		51		107		75
Transfers out of Level 3	(10)		(17)		(30)		(23)
Balance at end of period	181		296		181		296
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	27		216		34		33
Total increase (decrease) in unrealized losses included in cost of products sold	3	[1]	(161)	[2]	10	[3]	(151)	[4]
Purchases	2		10		6		186
Sales	(13)		(2)		(31)		(6)
Settlements	0		0		0		0
Transfers into Level 3	0		0		0		1
Transfers out of Level 3	0		0		0		0
Balance at end of period	19		63		19		63
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	320		171		261		138
Total increase (decrease) in unrealized losses included in cost of products sold	49	[1]	137	[2]	274	[3]	255	[4]
Purchases	0		0		0		0
Sales	0		0		0		0
Settlements	(238)		(109)		(450)		(211)
Transfers into Level 3	41		51		107		74
Transfers out of Level 3	(10)		(17)		(30)		(23)
Balance at end of period	$ 162		$ 233		$ 162		$ 233

[1] Includes increase in unrealized losses of $58 million relating to Level 3 liabilities still held at June 30, 2014.

[2] * Includes increase in unrealized losses of $8 million relating to Level 3 liabilities still held at June 30, 2013.

[3] * Includes increase in unrealized losses of $286 million relating to Level 3 liabilities still held at June 30, 2014.

[4] * Includes increase in unrealized losses of $110 million relating to Level 3 liabilities still held at June 30, 2013.