Supplementary Financial Statement Information (Schedule Of Interest Income And Interest Expense) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Supplementary Financial Statement Information [Abstract]
Interest expense	$ 669	$ 743	$ 596
Interest income	57	71	55
Capitalized interest costs	$ 17	$ 37	$ 22