Fair Value Measurements (Reconciliation Of Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	$ 295	$ 171
Total increase (decrease) in unrealized gains included in cost of products sold	556	333
Purchases	29	219
Sales	(45)	(26)
Settlements	(785)	(550)
Transfers into Level 3	256	197
Transfers out of Level 3	(54)	(49)
Balance at end of period	252	295
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 gains included in cost of products sold	534	524
Purchases	0	0
Sales	0	0
Settlements	(785)	(550)
Transfers into Level 3	256	197
Transfers out of Level 3	(54)	(48)
Balance at end of period	212	261
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 gains included in cost of products sold	22	(191)
Purchases	29	219
Sales	(45)	(26)
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	(1)
Balance at end of period	$ 40	$ 34