v2.4.0.6
Reconciliation of Tax Contingencies (Parenthetical) (Detail) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Income Tax Contingency [Line Items]        
Tax contingencies $ 294 [1] $ 229 [1] $ 213 [1] $ 181
Amount of tax contingencies, if fully recognized, which would decrease effective tax rate $ 294      
[1] As of December 31, 2012, we had $294 million of tax contingencies all of which, if fully recognized, would decrease our effective tax rate.