Summary Of Significant Accounting Policies Summary Of Significant Accounting Policies (Schedule Of Inventories) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
LIFO inventories
FIFO value	$ 1,408	$ 1,356
LIFO valuation reserve	(297)	(522)
LIFO inventories carrying value	1,111	834
FIFO inventories	3,741	5,232
Market inventories	6,059	7,036
Supplies and other inventories	530	734
Total inventories	$ 11,441	$ 13,836