Benefit Plans (Changes In Benefit Obligations Of Postemployment Plans) (Details) (Post-Employment [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Post-Employment [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of year	$ 270	$ 151
Service cost	1	1	1
Interest cost	1	2	1
Benefits paid	(143)	(48)
Actuarial losses and assumption changes	27	43
Other	(7)	121	5
Benefit obligation at end of year	$ 149	$ 270	$ 151