Amounts Recognized on Balance Sheets Related to Qualified Defined Benefit Pension Plans and Retiree Medical and Life Insurance PlansDisclosure - Amounts Recognized on Balance Sheets Related to Qualified Defined Benefit Pension Plans and Retiree Medical and Life Insurance Plans (Parenthetical) (Detail) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive loss, after tax	[1]	$ (11,444)	$ (11,870)	$ (9,601)	$ (13,493)
Qualified defined benefit pension plans
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive loss before tax	[2]	16,067	16,809
Accumulated other comprehensive loss after tax		10,400	10,800
Retiree medical and life insurance plans
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive loss before tax	[2]	794	755
Accumulated other comprehensive loss after tax		514	488
Other Plans
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive loss before tax		620	692
Accumulated other comprehensive loss after tax		408	460
Postretirement Benefit Plan Adjustments
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive loss, after tax	[1]	$ (11,314)	$ (11,813)	$ (9,649)	$ (13,532)

[1] AOCL related to postretirement benefit plans is shown net of tax benefits at December 31, 2015, 2014 and 2013 of $6.2 billion, $6.4 billion and $5.3 billion. These tax benefits include amounts recognized on our income tax returns as current deductions and deferred income taxes, which will be recognized on our tax returns in future years. See Note 9 and Note 11 for more information on our income taxes and postretirement benefit plans.

[2] Accumulated other comprehensive loss related to postretirement benefit plans, after tax, of $11.3 billion and $11.8 billion at December 31, 2015 and 2014 (Note 12) includes $16.1 billion ($10.4 billion after tax) and $16.8 billion ($10.8 billion after tax) for qualified defined benefit pension plans, $794 million ($514 million after tax) and $755 million ($488 million after tax) for retiree medical and life insurance plans and $620 million ($408 million after tax) and $692 million ($460 million after tax) for other plans.