Fair Value Measurements (Reconciliation Of Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 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)	$ 228		$ 117
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	295		171
Total increase (decrease) in unrealized losses included in cost of products sold	232	[1]	128	[2]
Purchases	4		176
Sales	(18)		(4)
Settlements	(212)		(102)
Transfers into Level 3	66		24
Transfers out of Level 3	(20)		(6)
Balance at end of period	347		387
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	34		33
Total increase (decrease) in unrealized losses included in cost of products sold	7	[1]	10	[2]
Purchases	4		176
Sales	(18)		(4)
Settlements	0		0
Transfers into Level 3	0		1
Transfers out of Level 3	0		0
Balance at end of period	27		216
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	261		138
Total increase (decrease) in unrealized losses included in cost of products sold	225	[1]	118	[2]
Purchases	0		0
Sales	0		0
Settlements	(212)		(102)
Transfers into Level 3	66		23
Transfers out of Level 3	(20)		(6)
Balance at end of period	$ 320		$ 171

[1] Includes increase in unrealized losses of $228 million relating to Level 3 liabilities still held at March 31, 2014.

[2] * Includes increase in unrealized losses of $117 million relating to Level 3 liabilities still held at March 31, 2013.