Shareholders' Equity And Net Income Per Share Share Repurchase Program (Details) (USD $)
3 Months Ended 1 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Apr. 29, 2015
Apr. 30, 2015
Share Repurchase Program [Line Items]        
Stock Repurchased During Period, Shares 3,233,146 2,376,391    
Stock Repurchased, Average Price per Share $ 74.17 $ 66.14    
Stock Repurchased During Period, Value $ 240,000,000 $ 157,000,000    
Share Repurchase Program January 2014        
Share Repurchase Program [Line Items]        
Stock Repurchase Program, Authorized Amount 1,000,000,000      
Share Repurchase Program January 2015        
Share Repurchase Program [Line Items]        
Stock Repurchase Program, Authorized Amount 1,500,000,000      
Stock Repurchase Program, Remaining Authorized Repurchase Amount 1,426,000,000      
Subsequent Event        
Share Repurchase Program [Line Items]        
Stock Repurchased During Period, Value     80,000,000  
Subsequent Event | Share Repurchase Program January 2015        
Share Repurchase Program [Line Items]        
Stock Repurchase Program, Remaining Authorized Repurchase Amount       $ 1,346,000,000