v2.4.0.6
Employee Benefits, Components of Net Periodic Benefit Cost (Details) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Other Changes In Plan Assets And Benefit Obligations Recognized In Other Comprehensive Income:      
Net actuarial loss (gain) $ (1,079) $ 20 $ 222
Pension benefits qualified [Member]
      
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]      
Service cost 6 5 210
Interest cost 520 554 595
Expected return on plan assets (759) (717) (643)
Amortization of net actuarial loss 86 105 194
Amortization of prior service credit 0 0 0
Settlements 4 0 0
Curtailment loss (gain) 0 3 (32)
Net periodic benefit cost (income) (143) (50) 324
Other Changes In Plan Assets And Benefit Obligations Recognized In Other Comprehensive Income:      
Net actuarial loss (gain) 1,120 (59) (346)
Amortization of net actuarial loss (86) (105) (194)
Prior service cost 0 2 0
Amortization of prior service cost 0 0 0
Settlement (4) 0 0
Net loss (gain) in curtailment (3) (3) 32
Net gain on amendment 0 0 0
Translation adjustments (1) 0 3
Total recognized in other comprehensive income 1,026 (165) (505)
Total recognized in net periodic benefit cost and other comprehensive income 883 (215) (181)
Pension benefits non-qualified [Member]
      
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]      
Service cost 1 0 8
Interest cost 34 37 43
Expected return on plan assets 0 0 0
Amortization of net actuarial loss 6 3 2
Amortization of prior service credit 0 0 (1)
Settlements 3 0 0
Curtailment loss (gain) 0 0 (33)
Net periodic benefit cost (income) 44 40 19
Other Changes In Plan Assets And Benefit Obligations Recognized In Other Comprehensive Income:      
Net actuarial loss (gain) 33 46 25
Amortization of net actuarial loss (6) (3) (2)
Prior service cost 0 0 0
Amortization of prior service cost 0 0 1
Settlement (3) 0 0
Net loss (gain) in curtailment 0 0 33
Net gain on amendment 0 0 0
Translation adjustments 0 0 0
Total recognized in other comprehensive income 24 43 57
Total recognized in net periodic benefit cost and other comprehensive income 68 83 76
Other benefits [Member]
      
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]      
Service cost 13 13 13
Interest cost 71 78 83
Expected return on plan assets (41) (29) (29)
Amortization of net actuarial loss 0 1 3
Amortization of prior service credit (3) (4) (3)
Settlements 0 0 0
Curtailment loss (gain) 0 (4) 0
Net periodic benefit cost (income) 40 55 67
Other Changes In Plan Assets And Benefit Obligations Recognized In Other Comprehensive Income:      
Net actuarial loss (gain) (74) (9) 99
Amortization of net actuarial loss 0 (1) (3)
Prior service cost 0 0 0
Amortization of prior service cost 3 4 3
Settlement 0 0 0
Net loss (gain) in curtailment 0 4 0
Net gain on amendment 0 0 (54)
Translation adjustments 0 0 2
Total recognized in other comprehensive income (71) (2) 47
Total recognized in net periodic benefit cost and other comprehensive income $ (31) $ 53 $ 114