Income Taxes (Tax Effects Of Temporary Differences Between Reported Earnings And Taxable Earnings) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Retirement benefits	$ 1,398	[1]	$ 1,052	[1]
Tax loss and credit carryforwards	410		335
Salaries and wages	258		254
Workers' compensation	222		215
Other	521		447
Deferred assets	2,904		2,391
Valuation allowance	(102)		(83)
Net deferred assets	2,802		2,308
Intangible assets	(1,137)		(1,159)
Contract accounting methods	(626)		(649)
Capital Construction Fund	(239)		(239)
Other	(522)		(475)
Deferred liabilities	(2,524)		(2,522)
Net deferred tax asset (liability)	278		(214)
ATwelve Contract [Member]
A-12 Termination	$ 95		$ 88

[1] Includes a deferred tax asset of $1,250 on December 31, 2010, and $1,634 on December 31, 2011, related to the amounts recorded in accumulated other comprehensive income to recognize the funded status of our retirement plans. See Notes L and P for further discussion.