Fair Value Measurements (Reconciliation Of Liabilities Measured At Fair Value On A Recurring Basis) (Details) (Significant Unobservable Inputs (Level 3) [Member], Fair Value, Measurements, Recurring [Member], USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013
Inventory Related Payables [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	$ 38	$ 33
Total increase (decrease) in unrealized gains included in cost of products sold	1	(191)
Purchases	8	219
Sales	(17)	(26)
Transfers into Level 3	3	0
Transfers out of Level 3		(1)
Balance at end of period	33	34
Commodity Derivative Contracts Losses [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	179	138
Total increase (decrease) in unrealized gains included in cost of products sold	139	524
Settlements	(235)	(550)
Transfers into Level 3	101	197
Transfers out of Level 3	(46)	(48)
Balance at end of period	138	261
Total Liabilities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	217	171
Total increase (decrease) in unrealized gains included in cost of products sold	140	333
Purchases	8	219
Sales	(17)	(26)
Settlements	(235)	(550)
Transfers into Level 3	104	197
Transfers out of Level 3	(46)	(49)
Balance at end of period	$ 171	$ 295