v3.3.1.900
Restricted Stock Units and Awards Activity (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Compensation expense not yet recognized related to non-vested RSUs and RSAs $ 82    
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition 1 year 8 months    
Excess tax benefit for equity-based compensation   $ 5 $ 10
Restricted Stock Units (RSUs) [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Non-vested at January 1 2.8    
Granted 1.1    
Vested (1.6)    
Forfeited (0.2)    
Non-vested at December 31 2.1 2.8  
Non-vested at January 1 $ 60.11    
Granted 67.46    
Vested 57.50    
Forfeited 66.94    
Non-vested at December 31 $ 65.06 $ 60.11  
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition 2 years 8 months 12 days