v2.4.0.6
Future Principal Payment for Debt (Detail) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Long Term Debt Maturities Repayments Of Principal [Line Items]    
2013 $ 579  
2014 46  
2015 816  
2016     
2017 1,000  
Thereafter 1,250  
Long-term debt $ 3,691 $ 384