v2.4.0.6
Identified Intangible Assets - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]    
Intangible assets, net of accumulated amortization and impairments $ 965 $ 1,171
Expected weighted average remaining life of identified intangibles 6 years  
Software [Member]
   
Finite-Lived Intangible Assets [Line Items]    
Expected weighted average remaining life of identified intangibles 2 years