v2.4.0.6
Share-Based Compensation (Narrative) (Details) (USD $)
In Millions, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Total shares of common stock reserved for issuance pursuant to the 2009 Long-Term Incentive Plan 21,500,000    
Number of shares used to calculate shares issued under the 2009 Long-Term Incentive Plan, options granted 1    
Number of shares used to calculate shares issued under the 2009 Long-Term Incentive Plan, other awards 1.84    
Aggregate intrinsic value of stock options exercised $ 81 $ 47 $ 51
Aggregate fair value of restricted stock awards vested 145 184 165
Common shares awarded based upon total shareholder return 341,000    
Stock Options [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unrecognized compensation cost 70    
Unrecognized compensation cost, weighted-average period of recognition (in years) 3.0    
Restricted Stock Awards And Units [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unrecognized compensation cost 305    
Unrecognized compensation cost, weighted-average period of recognition (in years) 2.8    
Performance Based Restricted Stock Awards [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unrecognized compensation cost 4    
Unrecognized compensation cost, weighted-average period of recognition (in years) 2.4    
Performance Share Units [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unrecognized compensation cost $ 8    
Unrecognized compensation cost, weighted-average period of recognition (in years) 2.3    
Maximum [Member] | Performance Share Units [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Units able to vest as a percentage of granted shares 200.00%    
Minimum [Member] | Performance Share Units [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Units able to vest as a percentage of granted shares 0.00%