Acquisition And Restructuring Costs (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2011 employees	Dec. 31, 2011	Dec. 31, 2010 employees	Dec. 31, 2009
Business Acquisition [Line Items]
Acquisition and restructuring costs		$ 16	$ 89	$ 49
Additional restructuring-related accruals		133	156
Number of employees involuntarily terminated	442	782	1,400
Percentage of global workforce		5.00%
Tax benefit related to acquisition		55
Restructuring charges	120	253	156
Intesa, Mourant International Finance Administration And BIAM [Member]
Business Acquisition [Line Items]
Acquisition and restructuring costs		71
Business Operations And Information Technology Transformation Program [Member]
Business Acquisition [Line Items]
Number of employees involuntarily terminated		530
Restructuring charges		133
Employee Severance [Member]
Business Acquisition [Line Items]
Number of employees involuntarily terminated		1,930
Involuntarily Terminated [Member]
Business Acquisition [Line Items]
Number of employees involuntarily terminated		1,332
Pre-Tax Restructuring Charges [Member]
Business Acquisition [Line Items]
Additional restructuring-related accruals		289
Withdrawal From Fixed-Income Trading Initiative [Member]
Business Acquisition [Line Items]
Restructuring charges		$ 120
Expenses Control Measures [Member]
Business Acquisition [Line Items]
Number of employees involuntarily terminated		15