Acquisitions, Divestitures, Goodwill and Intangible Assets - Intangible Assets (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended													3 Months Ended	12 Months Ended	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Contract and Program Intangible Assets		Dec. 31, 2011 Contract and Program Intangible Assets		Dec. 31, 2012 Tradenames and Trademarks	Dec. 31, 2011 Tradenames and Trademarks	Dec. 31, 2012 Technology and Software	Dec. 31, 2011 Technology and Software	Dec. 31, 2012 Other Intangible Assets	Dec. 31, 2011 Other Intangible Assets	Dec. 31, 2012 Aerospace Contract and Program Intangible Assets	Dec. 31, 2011 Aerospace Contract and Program Intangible Assets	Dec. 31, 2012 Information Systems and Technology Contract and Program Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,915	$ 3,219		$ 2,066	[1]	$ 2,393	[1]	$ 494	$ 477	$ 180	$ 175	$ 175	$ 174
Accumulated Amortization	(1,532)	(1,406)		(1,165)	[1]	(1,060)	[1]	(87)	(70)	(108)	(110)	(172)	(166)
Net Carrying Amount	1,383	1,813		901	[1]	1,333	[1]	407	407	72	65	3	8
Impairment of the contract and program intangible asset	$ 2,295	$ 111	$ 0											$ 191	$ 111	$ 110

[1] Consists of acquired backlog and probable follow-on work and related customer relationships.