Reconciliation of Benefit Obligations, Plan Assets, and Unfunded or Funded Status (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Change in plan assets
Fair value of plan assets at beginning of year		$ 36,605
Fair value of plan assets at end of year		33,909	$ 36,605
Qualified defined benefit pension plans
Change in benefit obligation
Benefit obligations at beginning of year		45,882	42,161
Service cost	[1]	875	903	$ 1,142
Interest cost	[1]	1,791	1,912	1,800
Benefits paid	[2]	(2,055)	(2,399)
Actuarial losses (gains)		(1,988)	4,493
New longevity assumptions		(834)	3,390
Plan amendments and acquisitions	[3]	31	(4,578)
Benefit obligations at end of year		43,702	45,882	42,161
Change in plan assets
Fair value of plan assets at beginning of year		34,673	33,010
Actual return on plan assets		(527)	2,062
Benefits paid	[2]	(2,055)	(2,399)
Company contributions		5	2,000
Fair value of plan assets at end of year		32,096	34,673	33,010
Unfunded status of the plans		(11,606)	(11,209)
Retiree medical and life insurance plans
Change in benefit obligation
Benefit obligations at beginning of year		3,034	2,823
Service cost		21	22	27
Interest cost		110	123	116
Benefits paid	[2]	(307)	(352)
Actuarial losses (gains)		(170)	(40)
New longevity assumptions		(77)	266
Plan amendments and acquisitions	[3]	157	5
Medicare Part D subsidy		14	26
Participants' contributions		101	161
Benefit obligations at end of year		2,883	3,034	2,823
Change in plan assets
Fair value of plan assets at beginning of year		1,932	1,921
Actual return on plan assets		(27)	126
Benefits paid	[2]	(307)	(352)
Company contributions		100	50
Medicare Part D subsidy		14	26
Participants' contributions		101	161
Fair value of plan assets at end of year		1,813	1,932	$ 1,921
Unfunded status of the plans		$ (1,070)	$ (1,102)

[1] Total net periodic benefit cost associated with our qualified defined benefit plans represents pension expense calculated in accordance with GAAP (FAS pension expense). We are required to calculate pension expense in accordance with both GAAP and CAS rules, each of which results in a different calculated amount of pension expense. The CAS pension cost is recovered through the pricing of our products and services on U.S. Government contracts and, therefore, is recognized in net sales and cost of sales for products and services. We include the difference between FAS pension expense and CAS pension cost, referred to as the FAS/CAS pension adjustment, as a component of other unallocated, net on our Statements of Earnings. The FAS/CAS pension adjustment, which was income of $471 million in 2015; income of $376 million in 2014; and expense of $482 million in 2013, effectively adjusts the amount of CAS pension cost in the business segment operating profit so that pension expense recorded on our Statements of Earnings is equal to FAS pension expense.

[2] Benefits paid in 2014 for qualified defined benefit pension plans include $427 million in the form of lump-sum settlement payments to former employees who had not commenced receiving their vested benefit payments. The corresponding benefit obligation that was released was $529 million. The settlement payments had no impact on our 2014 FAS pension expense and CAS pension cost.

[3] The June 2014 plan amendment which resulted in freezing the pay-based component of the formula used to determine retirement benefits under the affected plans reduced our qualified defined benefit pension obligations by $4.6 billion, which resulted in a corresponding reduction, net of tax, in the accumulated other comprehensive loss (AOCL) component of stockholders' equity. This amount is being recognized as a reduction of net periodic benefit cost (i.e., amortization of net prior service credit) over the estimated remaining service period of the covered employees, which is approximately 10 years and began in the third quarter of 2014.