Stock-Based Compensation (Stock-Based Compensation Costs) (Details) (USD $)
In Millions
3 Months Ended
Apr. 30, 2011
May 01, 2010
Stock-Based Compensation    
Stock awards (shares and units) $ 6 $ 4
Stock options 7 8
Total stock-based compensation 13 12
Total related income tax benefits $ 5 $ 5