Acquisition And Restructuring Costs (Activity Related To Restructuring-Related Accruals) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 securities employees years	Sep. 30, 2010	Dec. 31, 2010 employees years	Sep. 30, 2011 Intesa, Mourant International Finance Administration And BIAM [Member]	Sep. 30, 2011 Intesa, Mourant International Finance Administration And BIAM [Member]	Sep. 30, 2011 Business Operations And Information Technology Transformation Program [Member]	Jun. 30, 2011 Business Operations And Information Technology Transformation Program [Member] employees	Sep. 30, 2011 Business Operations And Information Technology Transformation Program [Member]	Sep. 30, 2011 Employee-Related Costs [Member]	Dec. 31, 2010 Employee-Related Costs [Member]	Sep. 30, 2011 Real Estate Consolidation [Member]	Dec. 31, 2010 Real Estate Consolidation [Member]	Sep. 30, 2011 Employee Severance [Member] employees	Sep. 30, 2011 Involuntarily Termination [Member] employees	Sep. 30, 2011 IT Transition Costs [Member]	Sep. 30, 2011 Pre-Tax Restructuring Charges [Member]
Business Acquisition [Line Items]
Acquisition and restructuring costs								$ 66		$ 75
Acquisition and restructuring costs	85	23	121	77
Acquisition and restructuring costs						19	46
Number of employees involuntarily terminated			710		1,400				530						1,930	1,260
Percentage of global workforce					5.00%
Beginning balance			137								90		47
Additional restructuring-related accruals			75		156						53	105	5	51			17	231
Payments			(82)		(19)						(66)	(15)	(12)	(4)			(4)
Ending balance	$ 130		$ 130		$ 137						$ 77	$ 90	$ 40	$ 47			$ 13