Goodwill and Identifiable Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 25, 2015	Sep. 25, 2015	Jun. 26, 2015	Dec. 31, 2014
Goodwill [Line Items]
Goodwill	$ 7,112	$ 7,112		$ 7,501
Goodwill, non-cash impairment charge	491	491
Accumulated goodwill impairment losses	549	549
NSS [Member]
Goodwill [Line Items]
Goodwill	515	515	$ 1,006	1,006
Goodwill, non-cash impairment charge	491	491
Goodwill, non-cash impairment charge after income taxes	463
Accumulated goodwill impairment losses	491	491
Electronic Systems [Member]
Goodwill [Line Items]
Goodwill	3,895	$ 3,895		3,773
Goodwill, non-cash impairment charge
Accumulated goodwill impairment losses	43	$ 43
Communication Systems [Member]
Goodwill [Line Items]
Goodwill	1,003	$ 1,003		$ 992
Goodwill, non-cash impairment charge
Accumulated goodwill impairment losses	$ 15	$ 15