Schedule Of Net Periodic Benefit Cost (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Qualified Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,055	[1]	$ 974	[1]	$ 903	[1]
Interest cost	1,884	[1]	1,918	[1]	1,876	[1]
Expected return on plan assets	(2,187)	[1]	(2,033)	[1]	(2,027)	[1]
Recognized net actuarial losses	1,116	[1]	880	[1]	595	[1]
Amortization of prior service cost (credit) and other	73	[1]	82	[1]	95	[1]
Total net periodic benefit cost	1,941	[1]	1,821	[1]	1,442	[1]
Retiree Medical And Life Insurance Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	28		32		36
Interest cost	131		162		166
Expected return on plan assets	(131)		(140)		(129)
Recognized net actuarial losses	32		34		25
Amortization of prior service cost (credit) and other	(12)		(16)		(16)
Total net periodic benefit cost	$ 48		$ 72		$ 82

[1] Total net periodic benefit cost associated with our qualified defined benefit plans represents pension expense calculated in accordance with GAAP (FAS 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 expense 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 expense and CAS expense, referred to as the non-cash FAS/CAS pension adjustment ($(830) million in 2012, $(922) million in 2011, and $(454) million in 2010), as a component of other unallocated costs on our Statements of Earnings. The non-cash FAS/CAS pension adjustment effectively adjusts the amount of CAS pension expense in the business segment operating profit so that pension expense recorded on our Statements of Earnings is equal to FAS expense.