v2.4.0.8
Share-Based Compensation Plans (Details) (USD $)
In Millions, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Share Based Compensation Plans      
Shares authorized under the plan 36,000,000    
Shares available for grant under the plan 7,900,000    
Total unrecognized compensation costs related to all unvested share based awards $ 93    
Weighted average period over compensation costs are expected to be recognized 1 year 8 months 12 days    
Additional share based compensation expense in connection with modification of share-based awards 22 4 3
Stock options
     
Share Based Compensation Plans      
General term of awards after they are vested 10 years    
Weighted-average grant-date fair value per share      
Granted (in dollars per share) $ 17.37 $ 18.87 $ 19.75
Option valuation assumptions      
Dividend yield (as a percent) 2.00%   4.00%
Expected price volatility (as a percent) 39.00% 43.00% 40.00%
Risk free interest rate (as a percent) 0.94% 0.87% 1.97%
Expected life of options 5 years 3 months 18 days 5 years 4 years 10 months 24 days
Granted (in dollars per share) $ 17.37 $ 18.87 $ 19.75
Stock appreciation rights
     
Share Based Compensation Plans      
General term of awards after they are vested 10 years    
Time-based awards
     
Share Based Compensation Plans      
Vesting period 3 years    
Time-based awards | Stock options
     
Stock option activity      
Outstanding at the beginning of the period (in shares) 1,616,055    
Granted (in shares) 455,915 395,673 194,342
Exercised (in shares) (102,254) (264,707) (210,997)
Forfeited (in shares) (102,973)    
Expired (in shares) (12,579)    
Outstanding at the end of the period (in shares) 1,854,164 1,616,055  
Vested and exercisable at the end of the period (in shares) 1,176,140    
Total grant-date fair value of awards vested 7 5 8
Weighted-average exercise price per share      
Outstanding at the beginning of the period (in dollars per share) $ 71.69    
Granted (in dollars per share) $ 59.30    
Exercised (in dollars per share) $ 36.64    
Forfeited (in dollars per share) $ 56.97    
Expired (in dollars per share) $ 27.15    
Outstanding at the end of the period (in dollars per share) $ 71.49 $ 71.69  
Vested and exercisable at the end of the period (in dollars per share) $ 79.25    
Weighted-average remaining contractual term      
Outstanding 6 years 6 months 18 days 6 years 3 months 18 days  
Vested and exercisable at the end of the period 5 years 3 months 25 days    
Aggregate intrinsic value (in millions)      
Exercised during the period 5 3 5
Additional disclosure      
Aggregate intrinsic value 0 0  
Unvested options outstanding (in shares) 678,024    
Weighted-average grant-date fair value per share      
Granted (in dollars per share) $ 17.37 $ 18.87 $ 19.75
Option valuation assumptions      
Granted (in dollars per share) $ 17.37 $ 18.87 $ 19.75
Time-based awards | Restricted shares
     
Equity instruments other than options activity      
Vested (in shares) 0 0 (3,939)
Additional disclosure      
Total grant date fair value     1
Time-based awards | Deferred units
     
Equity instruments other than options activity      
Outstanding at the beginning of the period (in shares) 2,870,051    
Granted (in shares) 1,691,029 2,183,853 1,090,747
Vested (in shares) (1,556,840) 1,064,359 832,252
Forfeited (in shares) (271,912)    
Outstanding at the end of the period (in shares) 2,732,328 2,870,051  
Weighted-average grant-date fair value per share      
Outstanding at the beginning of the period (in dollars per share) $ 58.09    
Granted (in dollars per share) $ 58.91 $ 50.07 $ 77.55
Vested (in dollars per share) $ 61.32    
Forfeited (in dollars per share) $ 57.28    
Outstanding at the end of the period (in dollars per share) $ 56.84 $ 58.09  
Additional disclosure      
Total grant date fair value 95 74 66
Time-based awards | Stock appreciation rights
     
Additional disclosure      
Aggregate intrinsic value 0 0  
Unvested options outstanding (in shares) 0    
Equity instruments other than options activity      
Outstanding at the beginning of the period (in shares) 187,739    
Outstanding at the end of the period (in shares) 187,739 187,739  
Vested and exercisable at the end of the period (in shares) 187,739    
Weighted average exercise price per share      
Outstanding at the beginning of the period (in dollars per share) $ 93.39 $ 93.39  
Outstanding at the end of the period (in dollars per share) $ 93.39 $ 93.39  
Vested and exercisable at the end of the period (in dollars per share) $ 93.39    
Weighted-average remaining contractual term      
Outstanding 2 years 9 months 4 days 3 years 9 months 4 days  
Vested and exercisable, at the end of the period 2 years 9 months 4 days    
Additional disclosure      
Exercises (in shares) 0 0 1,400
Total pre-tax intrinsic value of stock appreciation rights exercised     0
Performance-based awards
     
Share Based Compensation Plans      
Number of equal installments vesting 1    
Performance-based awards | Stock options
     
Stock option activity      
Outstanding at the beginning of the period (in shares) 179,262    
Exercised (in shares) (7,385)    
Outstanding at the end of the period (in shares) 171,877 179,262  
Vested and exercisable at the end of the period (in shares) 171,877    
Weighted-average exercise price per share      
Outstanding at the beginning of the period (in dollars per share) $ 75.30    
Exercised (in dollars per share) $ 22.58    
Outstanding at the end of the period (in dollars per share) $ 77.57 $ 75.30  
Vested and exercisable at the end of the period (in dollars per share) $ 77.57    
Weighted-average remaining contractual term      
Outstanding 2 years 3 months 11 days 3 years 2 months 19 days  
Vested and exercisable at the end of the period 2 years 3 months 11 days    
Aggregate intrinsic value (in millions)      
Exercised during the period 0    
Additional disclosure      
Aggregate intrinsic value 0 0  
Unvested options outstanding (in shares) 0    
Two-year Awards
     
Share Based Compensation Plans      
Measurement period 2 years    
Three-year Awards
     
Share Based Compensation Plans      
Measurement period 3 years    
Market-based awards
     
Share Based Compensation Plans      
Number of equal installments vesting 1    
Market-based awards | Deferred units
     
Equity instruments other than options activity      
Outstanding at the beginning of the period (in shares) 231,451    
Granted (in shares) 171,001 163,319 98,797
Vested (in shares) (78,136)   0
Forfeited (in shares) (18,153)    
Outstanding at the end of the period (in shares) 306,163 231,451  
Weighted-average grant-date fair value per share      
Outstanding at the beginning of the period (in dollars per share) $ 65.50    
Granted (in dollars per share) $ 74.05 $ 58.52 $ 78.69
Vested (in dollars per share) $ 78.69    
Forfeited (in dollars per share) $ 69.87    
Outstanding at the end of the period (in dollars per share) $ 66.65 $ 65.50  
Additional disclosure      
Total grant date fair value $ 6 $ 24