v2.4.0.8
Stock-Based Compensation (Schedule of Non-qualified Stock Option Activity) (Details) (USD $)
In Millions, except Share data, unless otherwise specified
 6 Months Ended 12 Months Ended
Jun. 30, 2014
Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]    
Options, Outstanding 13,176,520 14,114,289
Options, Outstanding, Weighted Average Exercise Price $ 18.41 $ 18.25
Options, Outstanding, Weighted Average Remaining Contractual Term 2 years 4 months 26 days 3 years 1 month 6 days
Options, Outstanding, Intrinsic Value $ 73 $ 36
Options, Grants in Period, Gross 0  
Options, Grants in Period, Weighted Average Exercise Price $ 0.00  
Options, Exercises in Period 935,269  
Options, Exercises in Period, Weighted Average Exercise Price $ 16.04  
Options, Forfeitures in Period 0  
Options, Forfeitures in Period, Weighted Average Exercise Price $ 0.00  
Options, Expirations in Period 2,500  
Options, Expirations in Period, Weighted Average Exercise Price $ 17.79  
Options, Exercisable 12,313,723  
Options, Exercisable, Weighted Average Exercise Price $ 18.63  
Options, Exercisable, Weighted Average Remaining Contractual Term 2 years 1 month 6 days  
Options, Exercisable, Intrinsic Value 66  
Options, Vested and Expected to Vest, Outstanding 13,140,231  
Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price $ 18.42  
Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term 2 years 4 months 26 days  
Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value $ 73