v2.4.0.6
Debt - Long-Term Debt at Book Value (Detail) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Debt Instrument [Line Items]    
2013 $ 271 $ 17
2014 28  
2015 25  
2016 629  
2017 1,167  
Due after 5 years 1,336 1,846
Amount outstanding $ 3,456 $ 3,764