Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Fair Value Measurements (Details)

v2.4.0.6
Employee Benefit Plans - Fair Value Measurements (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 $ 21,729 $ 20,244    
Fixed Income Investments [Member] | US Treasury and Government [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 4,159 4,109    
Fixed Income Investments [Member] | Corporate Debt Securities [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 1,062 1,058    
Fixed Income Investments [Member] | Non-U.S. sovereign debt [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 615 542    
Fixed Income Investments [Member] | Mutual Funds [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 1,531 1,569    
Real Estate Investment [Member] | Private Real Estate [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 110 113    
Real Estate Investment [Member] | Mutual Funds [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 334 260    
Limited Partnerships [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 341 337    
Other Investments [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 694 [1] 708 [1]    
Fair Value, Inputs, Level 3 [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 817 739 672 670
Actual Return on Plan Assets Still Held at the Reporting Date 25 20 1  
Purchases 80 54 50  
Sales and Settlements (28) (8) (7)  
Transfers into/(out of) Level 3 1 1 (42)  
Fair Value, Inputs, Level 3 [Member] | Fixed Income Investments [Member] | US Treasury and Government [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 13 13 14  
Actual Return on Plan Assets Still Held at the Reporting Date 0 (1)    
Purchases 0 0    
Sales and Settlements 0 0    
Transfers into/(out of) Level 3 0 0    
Fair Value, Inputs, Level 3 [Member] | Fixed Income Investments [Member] | Corporate Debt Securities [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 0 0 14 0
Actual Return on Plan Assets Still Held at the Reporting Date     0  
Purchases     0  
Sales and Settlements     0  
Transfers into/(out of) Level 3     14  
Fair Value, Inputs, Level 3 [Member] | Fixed Income Investments [Member] | Non-U.S. sovereign debt [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 10 10 9 6
Actual Return on Plan Assets Still Held at the Reporting Date (1) 0 1  
Purchases 1 3 0  
Sales and Settlements (1) (2) 0  
Transfers into/(out of) Level 3 1 0 2  
Fair Value, Inputs, Level 3 [Member] | Fixed Income Investments [Member] | Mutual Funds [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 0 0    
Fair Value, Inputs, Level 3 [Member] | Real Estate Investment [Member] | Private Real Estate [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 110 113 110 119
Actual Return on Plan Assets Still Held at the Reporting Date (2) 0 (9)  
Purchases 2 3 1  
Sales and Settlements (3) 0 (1)  
Transfers into/(out of) Level 3 0 0 0  
Fair Value, Inputs, Level 3 [Member] | Real Estate Investment [Member] | Mutual Funds [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 324 249 215 195
Actual Return on Plan Assets Still Held at the Reporting Date 13 26 (4)  
Purchases 62 9 24  
Sales and Settlements 0 (1) 0  
Transfers into/(out of) Level 3 0 0 0  
Fair Value, Inputs, Level 3 [Member] | Limited Partnerships [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 231 232 230 162
Actual Return on Plan Assets Still Held at the Reporting Date 8 (6) 13  
Purchases 11 13 7  
Sales and Settlements (20) (5) (5)  
Transfers into/(out of) Level 3 0 0 53  
Fair Value, Inputs, Level 3 [Member] | Other Investments [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 129 [1] 122 [1] 94 188
Actual Return on Plan Assets Still Held at the Reporting Date 7 1 0  
Purchases 4 26 18  
Sales and Settlements (4) 0 (1)  
Transfers into/(out of) Level 3 $ 0 $ 1 $ (111)  
[1] Other investments include interest rate swaps of $311 million and $467 million, participant loans of $76 million and $75 million, commodity and balanced funds of $239 million and $116 million and other various investments of $68 million and $50 million at December 31, 2012 and 2011.