v2.4.0.6
Pension and Postretirement Benefit Plans - Amounts Recognized in Accumulated Other Comprehensive (Loss)/Income (Detail) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2011
Dec. 31, 2010
U.S. Qualified Pension Plans [Member]
    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial losses $ (4,638) [1] $ (2,699) [1]
Prior service (costs)/credits and other 123 63
Total (4,515) (2,636)
U.S. Supplemental (Non-Qualified) Pension Plans [Member]
    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial losses (566) [1] (525) [1]
Prior service (costs)/credits and other 26 21
Total (540) (504)
International Pension Plans [Member]
    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial losses (2,020) [1] (2,388) [1]
Prior service (costs)/credits and other (21) (18)
Total (2,041) (2,406)
Postretirement Plans [Member]
    
Defined Benefit Plan Disclosure [Line Items]    
Actuarial losses (759) [1] (451) [1]
Prior service (costs)/credits and other 468 581
Total $ (291) $ 130
[1] The actuarial losses primarily represent the cumulative difference between the actuarial assumptions and actual return on plan assets, changes in discount rates and changes in other assumptions used in measuring the benefit obligations. These actuarial losses are recognized in Accumulated other comprehensive income/(loss) and are amortized into net periodic benefit costs over an average period of 9.9 years for our U.S. qualified plans, an average period of 9.7 years for our U.S. supplemental (non-qualified) plans, an average period of 14 years for our international plans and an average period of 11.1 years for our postretirement plans.