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, 2011
Dec. 31, 2010
Dec. 31, 2009
Dec. 31, 2008
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 $ 20,244 $ 20,136    
Fixed Income Investments [Member] | US Treasury and Government [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 4,109 3,319    
Fixed Income Investments [Member] | Corporate Debt Securities [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 1,058 1,106    
Fixed Income Investments [Member] | Non-U.S. sovereign debt [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 542 465    
Fixed Income Investments [Member] | Mutual Funds [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 1,569 1,743    
Real Estate Investment [Member] | Private Real Estate [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 113 110    
Real Estate Investment [Member] | Mutual Funds [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 260 247    
Limited Partnerships [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 337 331    
Other Investments [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 708 [1] 343 [1]    
Fair Value, Inputs, Level 3 [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 739 672 670 821
Actual Return on Plan Assets Still Held at the Reporting Date 20 1 (214)  
Purchases 54 50 52  
Sales and Settlements (8) (7) (9)  
Transfers into/(out of) Level 3 1 (42) 20  
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 14 0  
Actual Return on Plan Assets Still Held at the Reporting Date (1) 0    
Purchases 0 0    
Sales and Settlements 0 0    
Transfers into/(out of) Level 3 0 14    
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 0 1
Actual Return on Plan Assets Still Held at the Reporting Date     (1)  
Purchases     0  
Sales and Settlements     0  
Transfers into/(out of) Level 3     0  
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 9 6 6
Actual Return on Plan Assets Still Held at the Reporting Date 0 1 0  
Purchases 3 0 0  
Sales and Settlements (2) 0 0  
Transfers into/(out of) Level 3 0 2 0  
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 31 113 110 119 149
Actual Return on Plan Assets Still Held at the Reporting Date 0 (9) (29)  
Purchases 3 1 0  
Sales and Settlements 0 (1) (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 31 249 215 195 281
Actual Return on Plan Assets Still Held at the Reporting Date 26 (4) (92)  
Purchases 9 24 6  
Sales and Settlements (1) 0 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 31 232 230 162 91
Actual Return on Plan Assets Still Held at the Reporting Date (6) 13 14  
Purchases 13 7 41  
Sales and Settlements (5) (5) (4)  
Transfers into/(out of) Level 3 0 53 20  
Fair Value, Inputs, Level 3 [Member] | Other Investments [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Fair Value, December 31 122 [1] 94 [1] 188 293
Actual Return on Plan Assets Still Held at the Reporting Date 1 0 (106)  
Purchases 26 18 5  
Sales and Settlements 0 (1) (4)  
Transfers into/(out of) Level 3 $ 1 $ (111) $ 0  
[1] Other investments represent interest rate swaps of $467 million and $198 million, participant loans of $75 million and $79 million, commodity and balanced funds of $116 million and $38 million and other various investments of $50 million and $28 million at December 31, 2011 and 2010.