Goodwill and Identifiable Intangible Assets, Allocated by Reportable Segment (Details) $ in Millions		12 Months Ended
		Dec. 31, 2017 USD ($) Employee	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Goodwill [Line Items]
Approximate number of employees | Employee		31,000
Goodwill [Roll Forward]
Goodwill		$ 6,719	$ 6,478	$ 6,199
Accumulated impairment losses		(104)	(104)	(104)
Balance, Beginning		6,374	6,095
Business acquisitions	[1]	212	335
Business divestitures	[2]	(12)
Foreign currency translation adjustments		93	(56)
Assets held for sale	[3]	(52)
Balance, Ending		6,615	6,374
Electronic Systems [Member]
Goodwill [Roll Forward]
Goodwill		2,856	2,687	2,445
Accumulated impairment losses		(43)	(43)	(43)
Balance, Beginning		2,644	2,402
Business acquisitions	[1]	131	287
Business divestitures	[2]	(12)
Foreign currency translation adjustments		60	(45)
Assets held for sale	[3]	(10)
Balance, Ending		2,813	2,644
Aerospace Systems [Member]
Goodwill [Roll Forward]
Goodwill		1,146	1,174	1,167
Accumulated impairment losses		0	0	0
Balance, Beginning		1,174	1,167
Business acquisitions	[1]	0	0
Business divestitures	[2]	0
Foreign currency translation adjustments		14	7
Assets held for sale	[3]	(42)
Balance, Ending		1,146	1,174
Communication Systems [Member]
Goodwill [Roll Forward]
Goodwill		1,058	1,058	1,038
Accumulated impairment losses		(35)	(35)	(35)
Balance, Beginning		1,023	1,003
Business acquisitions	[1]	0	20
Business divestitures	[2]	0
Foreign currency translation adjustments		0	0
Assets held for sale	[3]	0
Balance, Ending		1,023	1,023
Sensor Systems [Member]
Goodwill [Roll Forward]
Goodwill		1,659	1,559	1,549
Accumulated impairment losses		(26)	(26)	$ (26)
Balance, Beginning		1,533	1,523
Business acquisitions	[1]	81	28
Business divestitures	[2]	0
Foreign currency translation adjustments		19	(18)
Assets held for sale	[3]	0
Balance, Ending		$ 1,633	$ 1,533

[1] For the year ended December 31, 2017, business acquisitions for the Electronic Systems segment included the acquisitions of the ETD, Doss Aviation and G-Air businesses and the purchase price allocation adjustments for the MacH and Aerosim business acquisitions. Business acquisitions for the Sensor Systems segment included primarily the Adaptive Methods, Open Water Power, OceanServer and Kigre business acquisitions. For the year ended December 31, 2016, business acquisitions for the Electronic Systems segment included the acquisitions of the MacH and Aerosim businesses and the final purchase price allocation for L3 CTC business acquisition. Business acquisition for the Communication Systems segment included the ATM business acquisition. Business acquisitions for the Sensor Systems segment included the Micreo business acquisition and the final purchase price allocation for the L3 ForceX business acquisition.

[2] The decrease for the Electronic Systems segment was due to the divestitures of Coleman and Aviation Jet Services during the quarterly period ended March 31, 2017.

[3] The Aerostructures businesses within the Company's Aerospace Systems segment are classified as held for sale as of December 31, 2017.