Stockholders' Equity (Common Stock Repurchase Program) (Details) (USD $)
In Millions, except Per Share data, unless otherwise specified
1 Months Ended 3 Months Ended 12 Months Ended
Mar. 05, 2011
Jul. 30, 2011
Apr. 30, 2011
Jan. 28, 2012
Stock Repurchase Program, Authorized Amount $ 900      
Stock Repurchased and Retired, Value   113 787 900
Stock Repurchased and Retired, Shares   3.0 21.0 24.0
Share Repurchase Program, Average Share Price       $ 36.98
Common Stock [Member]
       
Stock Repurchased and Retired, Value       12
Stock Repurchased and Retired, Shares       24.4
Additional Paid-in Capital [Member]
       
Stock Repurchased and Retired, Value       404
Reinvested Earnings/(Loss) [Member]
       
Stock Repurchased and Retired, Value       $ 484