Supplemental Disclosures Of Cash Flow Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Supplemental Disclosures Of Cash Flow Information [Abstract]
Cash paid for interest	$ 5	$ 6	$ 50	$ 50
Cash paid for income taxes		1		17
Noncash property changes	$ 60	$ 10	$ 70	$ 46