v2.4.0.8
Pension and Other Postretirement Benefit Plans - One Percentage Point Change in Health Care Cost Trend Rate (Detail) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Defined Benefit Plan, Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates [Abstract]  
Effect on total service and interest cost components, Increase $ 38
Effect on benefit obligation, Increase 316
Effect on total service and interest cost components, Decrease (30)
Effect on benefit obligation, Decrease $ (262)