CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) (Parenthetical) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Apr. 28, 2012
Apr. 30, 2011
Consolidated Statements of Comprehensive Income/(Loss) [Abstract]    
Tax expense/(benefit) on unrealized gain/(loss) on investments $ 16 $ 12
Tax expense/(benefit) on net unamortized gain/(loss) and prior service credit/(cost) $ 21 $ 12