Asset Impairment, Exit And Implementation Costs (Movement In The Severance Liability And Details Of Asset Impairment And Exit Costs) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012
Restructuring Cost and Reserve [Line Items]
Severance liability balance, December 31, 2011	$ 156
Charges	21
Cash spent	(35)
Other	(11)
Severance liability balance, March 31, 2012	131
Severance [Member]
Restructuring Cost and Reserve [Line Items]
Severance liability balance, December 31, 2011	156
Cash spent	(25)
Severance liability balance, March 31, 2012	131
Other [Member]
Restructuring Cost and Reserve [Line Items]
Charges	21
Cash spent	(10)
Other	$ (11)