Goodwill and Identifiable Intangible Assets - Changes in Goodwill by Segment (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Balance, Beginning	$ 7,472	$ 7,505
Business acquisitions	250	27
Impairment loss		(43)
Foreign currency translation	22	(17)
Balance, Ending	7,744	7,472
Electronic Systems [Member]
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Balance, Beginning	4,540	4,405
Business acquisitions	250	22
Impairment loss		(43)
Foreign currency translation	14	(12)
Segment reclassification		168
Balance, Ending	4,804	4,540
C3ISR [Member]
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Balance, Beginning		868
Business acquisitions		3
Segment reclassification		(74)
Balance, Ending	797	797
AM&M [Member]
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Balance, Beginning	1,169	1,172
Business acquisitions		2
Foreign currency translation	6	(5)
Balance, Ending	1,175	1,169
NSS [Member]
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Balance, Beginning	966	1,060
Foreign currency translation	2
Segment reclassification		(94)
Balance, Ending	$ 968	$ 966