Income Taxes (Tax Effects Of Temporary Differences Between Reported Earnings And Taxable Earnings) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Retirement benefits	$ 1,746	[1]	$ 1,398	[1]
Tax loss and credit carryforwards	561		410
Salaries and wages	261		258
Workers' compensation	260		222
Other	536		521
Deferred assets	3,458		2,904
Valuation allowance	(335)		(102)
Net deferred assets	3,123		2,802
Intangible assets	(950)		(1,137)
Contract accounting methods	(566)		(626)
Capital Construction Fund	(239)		(239)
Other	(390)		(522)
Deferred liabilities	(2,145)		(2,524)
Net deferred tax asset (liability)	978		278
A-12
A-12 Termination	$ 94		$ 95

[1] ncludes a deferred tax asset of $1.6 billion on December 31, 2011, and $2.1 billion on December 31, 2012, related to the amounts recorded in accumulated other comprehensive loss (AOCI) to recognize the funded status of our retirement plans. See Notes L and P for further discussion.