Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Fair Value Measurements Rollforward (Details)

v3.3.1.900
Employee Benefit Plans - Fair Value Measurements Rollforward (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Change in fair value of plan assets      
Fair value, January 1 $ 24,133    
Fair value, December 31 23,505 $ 24,133  
U.S. government and agency securities      
Change in fair value of plan assets      
Fair value, January 1 4,166    
Fair value, December 31 3,615 4,166  
Non-U.S. debt securities      
Change in fair value of plan assets      
Fair value, January 1 1,114    
Fair value, December 31 1,294 1,114  
Private real estate      
Change in fair value of plan assets      
Fair value, January 1 127    
Fair value, December 31 144 127  
Real estate commingled/mutual funds      
Change in fair value of plan assets      
Fair value, January 1 636    
Fair value, December 31 743 636  
Limited partnerships      
Change in fair value of plan assets      
Fair value, January 1 187    
Fair value, December 31 170 187  
Other investments      
Change in fair value of plan assets      
Fair value, January 1 618    
Fair value, December 31 389 618  
Level 3      
Change in fair value of plan assets      
Fair value, January 1 962 879 $ 817
Actual Return on Plan Assets Still Held at the Reporting Date 45 31 19
Purchases, Sales and Settlements 30 56 71
Transfers out of Level 3 0 (4) (28)
Fair value, December 31 1,037 962 879
Level 3 | U.S. government and agency securities      
Change in fair value of plan assets      
Fair value, January 1 11 12 13
Actual Return on Plan Assets Still Held at the Reporting Date 0 0 0
Purchases, Sales and Settlements 0 (1) (1)
Transfers out of Level 3 0 0 0
Fair value, December 31 11 11 12
Level 3 | Non-U.S. debt securities      
Change in fair value of plan assets      
Fair value, January 1 0 6 10
Actual Return on Plan Assets Still Held at the Reporting Date   0 (2)
Purchases, Sales and Settlements   (2) (2)
Transfers out of Level 3   (4) 0
Fair value, December 31 0 0 6
Level 3 | Private real estate      
Change in fair value of plan assets      
Fair value, January 1 127 119 110
Actual Return on Plan Assets Still Held at the Reporting Date 14 5 4
Purchases, Sales and Settlements 3 3 5
Transfers out of Level 3 0 0 0
Fair value, December 31 144 127 119
Level 3 | Real estate commingled/mutual funds      
Change in fair value of plan assets      
Fair value, January 1 632 462 324
Actual Return on Plan Assets Still Held at the Reporting Date 37 20 15
Purchases, Sales and Settlements 62 150 123
Transfers out of Level 3 0 0 0
Fair value, December 31 731 632 462
Level 3 | Limited partnerships      
Change in fair value of plan assets      
Fair value, January 1 65 145 231
Actual Return on Plan Assets Still Held at the Reporting Date (1) 5 8
Purchases, Sales and Settlements (15) (85) (66)
Transfers out of Level 3 0 0 (28)
Fair value, December 31 49 65 145
Level 3 | Other investments      
Change in fair value of plan assets      
Fair value, January 1 127 135 129
Actual Return on Plan Assets Still Held at the Reporting Date (5) 1 (6)
Purchases, Sales and Settlements (20) (9) 12
Transfers out of Level 3 0 0 0
Fair value, December 31 $ 102 $ 127 $ 135