Acquisition and Restructuring Costs (Activity Related To Restructuring-Related Accruals) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Restructuring Reserve [Roll Forward]
Balance as of December 31, 2012	$ 262
Additional accruals for Business Operations and Information Technology Transformation program	19
Additional accruals for 2012 expense control measures	3	(1)
Payments and adjustments	(148)
Balance as of September 30, 2013	136	262
Employee- Related Costs
Restructuring Reserve [Roll Forward]
Balance as of December 31, 2012	195
Additional accruals for Business Operations and Information Technology Transformation program	9
Additional accruals for 2012 expense control measures	(2)
Payments and adjustments	(125)
Balance as of September 30, 2013	77
Real Estate Consolidation
Restructuring Reserve [Roll Forward]
Balance as of December 31, 2012	49
Additional accruals for Business Operations and Information Technology Transformation program	11
Additional accruals for 2012 expense control measures	0
Payments and adjustments	(11)
Balance as of September 30, 2013	49
Information Technology Costs
Restructuring Reserve [Roll Forward]
Balance as of December 31, 2012	5
Additional accruals for Business Operations and Information Technology Transformation program	(1)
Additional accruals for 2012 expense control measures	0
Payments and adjustments	(4)
Balance as of September 30, 2013	0
Asset and Other Write-Offs
Restructuring Reserve [Roll Forward]
Balance as of December 31, 2012	13
Additional accruals for Business Operations and Information Technology Transformation program	0
Additional accruals for 2012 expense control measures	5
Payments and adjustments	(8)
Balance as of September 30, 2013	$ 10