Restructuring Charges And Other Items (Rollforward Of The Severance And Other Costs) (Details) (Employee Severance And Other Cost [Member], USD $) In Millions, unless otherwise specified	12 Months Ended		12 Months Ended			12 Months Ended
	Dec. 31, 2012 2012 Acitivity [Member]	Mar. 31, 2012 2012 Acitivity [Member]	Dec. 31, 2012 2011 Activity [Member]	Dec. 31, 2011 2011 Activity [Member]	Mar. 31, 2011 2011 Activity [Member]	Dec. 31, 2012 2010 Activity [Member]	Dec. 31, 2011 2010 Activity [Member]	Dec. 31, 2010 2010 Activity [Member]	Mar. 31, 2010 2010 Activity [Member]
Restructuring Cost and Reserve [Line Items]
Balance		$ 7			$ 7				$ 20
Additions and adjustments	24			18				26
Cash charges	(15)		(8)	(16)		(4)	(8)	(32)
Balance	$ 16	$ 7	$ 1		$ 7	$ 2			$ 20