v2.4.0.6
Changes in Carrying Amount of Goodwill as Allocated to Reportable Segments (Detail) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2012
Goodwill [Line Items]  
Balance at December 31, 2011 $ 1,161
Goodwill acquired and other changes during the period 67
Balance at December 31, 2012 1,228
Investor Services
 
Goodwill [Line Items]  
Balance at December 31, 2011 953
Goodwill acquired and other changes during the period 45
Balance at December 31, 2012 998
Institutional Services
 
Goodwill [Line Items]  
Balance at December 31, 2011 208
Goodwill acquired and other changes during the period 22
Balance at December 31, 2012 $ 230