v3.3.1.900
Goodwill - Goodwill Activity (Parenthetical) (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Goodwill [Line Items]    
Acquisitions $ 181 $ 0
Purchase price 300  
Contingent consideration at fair value 27  
Excess of tax goodwill over book goodwill 231 $ 263
FutureAdvisor [Member]    
Goodwill [Line Items]    
Acquisitions 113  
Infraestructura Institucional [Member]    
Goodwill [Line Items]    
Acquisitions 49  
BlackRock Kelso Capital Advisors LLC [Member]    
Goodwill [Line Items]    
Acquisitions $ 19