Acquisitions and Divestitures, Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Millions		Sep. 29, 2019	Dec. 31, 2018
Intangible Assets [Line Items]
Gross Carrying Amount	[1]	$ 4,564	$ 4,564
Accumulated Amortization		(2,188)	(1,979)
Net Carrying Amount		2,376	2,585
Contract and Program Intangible Assets
Intangible Assets [Line Items]
Gross Carrying Amount	[1],[2]	3,775	3,771
Accumulated Amortization	[2]	(1,717)	(1,531)
Net Carrying Amount	[2]	2,058	2,240
Trade Names and Trademarks
Intangible Assets [Line Items]
Gross Carrying Amount	[1]	465	469
Accumulated Amortization		(188)	(177)
Net Carrying Amount		277	292
Technology and Software
Intangible Assets [Line Items]
Gross Carrying Amount	[1]	165	165
Accumulated Amortization		(126)	(116)
Net Carrying Amount		39	49
Other Intangible Assets
Intangible Assets [Line Items]
Gross Carrying Amount	[1]	159	159
Accumulated Amortization		(157)	(155)
Net Carrying Amount		$ 2	$ 4

[1] Change in gross carrying amounts consists primarily of adjustments for acquired intangible assets and foreign currency translation.

[2] Consists of acquired backlog and probable follow-on work and associated customer relationships.