Acquisition And Restructuring Costs (Activity Related To Restructuring-Related Accruals) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Business Acquisition [Line Items]
Beginning balance	$ 287
Additional accruals for business operations and information technology transformation program	33
Accruals for expense control measures	(3)
Payments and adjustments	(128)
Ending balance	189
Employee-Related Costs [Member]
Business Acquisition [Line Items]
Beginning balance	162
Additional accruals for business operations and information technology transformation program	14
Accruals for expense control measures	1
Payments and adjustments	(69)
Ending balance	108
Real Estate Consolidation [Member]
Business Acquisition [Line Items]
Beginning balance	39
Additional accruals for business operations and information technology transformation program	6
Accruals for expense control measures	0
Payments and adjustments	(4)
Ending balance	41
IT Transition Costs [Member]
Business Acquisition [Line Items]
Beginning balance	33
Additional accruals for business operations and information technology transformation program	13
Accruals for expense control measures	0
Payments and adjustments	(23)
Ending balance	23
Fixed-Income Trading Portfolio [Member]
Business Acquisition [Line Items]
Beginning balance	38
Additional accruals for business operations and information technology transformation program	0
Accruals for expense control measures	(9)
Payments and adjustments	(26)
Ending balance	3
Asset And Other Write Offs [Member]
Business Acquisition [Line Items]
Beginning balance	15
Additional accruals for business operations and information technology transformation program	0
Accruals for expense control measures	5
Payments and adjustments	(6)
Ending balance	$ 14