v2.4.0.8
Benefit or Income Cost Related to Pension and Postretirement Health Care and Life Insurance Plans (Detail) (USD $)
In Millions, unless otherwise specified
3 Months Ended 6 Months Ended
Jun. 30, 2014
Jun. 30, 2013
Jun. 30, 2014
Jun. 30, 2013
Defined Benefit Plan Disclosure [Line Items]        
Remeasurement gain, net   $ (237)   $ (237)
Pension
       
Defined Benefit Plan Disclosure [Line Items]        
Service cost 82 98 163 197
Amortization of prior service cost (credit) (2) 2 (4) 3
Expected return on plan assets (295) (311) (590) (622)
Interest cost 259 251 518 501
Remeasurement gain, net   (237)   (237)
Net periodic benefit (income) cost 44 (197) 87 (158)
Health Care And Life
       
Defined Benefit Plan Disclosure [Line Items]        
Service cost 64 79 129 159
Amortization of prior service cost (credit) (64) (61) (127) (123)
Expected return on plan assets (40) (36) (81) (72)
Interest cost 277 274 554 548
Net periodic benefit (income) cost $ 237 $ 256 $ 475 $ 512